Suggestions

Spam for a Christmas present?

Yum, yum.

1.Realism doesn't allow that
2.Hide and mine them?, build there own defences and ships as well  .
3.Maybe, It sounds complicated
4.Good idea, would like to see
5.Agian, would like to see
6.It would be better then placeing 8 fleets of ships to defend one tiny starbase, I can tell you
7.Warnings for Noobs eh  
8.Would be better then the defences now
9.Already have intersectors, just lap them over if you want to slow them down more
10.*cough* GCI *cough*
11.Don't have DA   
12.Sliders are needed to tailer your econ.
13.It's the same component, should expand on that (I didn't get exactly were your movtive was directed)
14.Tatictal combat isn't popular with the devs.
15.Good idea, would like to see
16.Govener screen works fine for me and rally ponits.
17.Good idea, would like to see, but wouldn't work for the lower level weapons, so . . .   
18.not realistic for food, is with production
19.doesn't need to be upgraded, well sometimes it does
20.would save A LOT OF TIME   
21.ahhh . . no   
22.not realistic
23.these are events, but I would like to see a black market for evil civs. and revenue rasing centers for good.
24.Discussed on some other treads, I give it my   , I would to see missionaries for good civs. though.

Some of the stuff you suggested might sound good in theory, but it doesn't mean it would make the game more fun to play. I suggest that you select a theme, like civ events, and work from there. Make sure you **EXPLAIN** why, and/or how your suggestions would make the game better. Otherwise, what you are doing is spamming ideas.

The devs have much better things to do than to try to decipher your post.

Some of these are good, some have already been discussed, others are just really bad IMO (like satellites, missiles, minefields and all that junk).

-Spending sliders Get rid of them, why always be paying for industry production when you dont always use it? Tailor production costs to when you assign production. For instance you are building a scout, this scout has a 50 cost, the planet has 25MPS. So this scout project will you cost you 50 BCs, 25 for each turn. Same idea with research.

Heh. Been holding myself from bringing this up, thought it was just me.

-Sizemods A lvl 1 laser does the same damage output on a tiny ship as well as a huge ship, should remove sizemods from weapons.

This one I did (not just weapons though, but everything)!    Did you notice that for example the pic for Laser III, which is supposedly smaller than Laser I, gives the impression that it is actually bigger?     

-Weapon/Defense tech progression Instead of 4-5 levels make it 3 levels. First research gives a prototype laser(higher cost, space, lesser dmg), then a fully operational laser(normal stats), then an enhanced laser(more dmg, lesser cost and space). Rinse repeat with others.

The techtree is somewhat of an enigma to me. If it wasn't for miniaturization, it could be somewhat logical to have size reduced with each step. BUT then you have Barriers I have a different defense value than Barriers II, and other examples (probably due to tweaking, but the names weren't adjusted). The propulsion branch could be better too, and the sensors (why not call Scanners / Deep Space Scanners to the sensors with range 2, to make a difference?).

-Trade offs Buy credits with unused production/food.

That could make building farms (with no need to) actually productive. Especially in bonus tiles. The domestic trading that some people want in the game?

-Speed in combat Incorporate speed into defense/ability to escape ratings.

Ships don't do battle with their HDs on    In order to introduce combat speed, as good as it would be, it'd require an entirely new combat model.

-Stargate New starbase like building that allows ships and fleets to "gate" to any explored square/sector on the map

This was one of the ways to deal with the speed issue already mentioned in other threads.

Ok i'll go further in depth with these:

[Production - Queueing - Build Orders]
First I would propose a fundemental change to the way that improvements and ships are produced. The change is from a single project focus to a multiple project focus. Instead of world concentrating all industry on building a single ship and or planet improvement you have the option of distributing the building process across the board allowing either 1 ship to get built really fast then moving on to the next one or 10 ships to be built in a longer period of time and finish construction together.

If building 1 ship really fast and there are excess industry points left over then that excess moves over to start the next ship in the process. IE: 50 points, 2 35point scouts being built. First scout gets 35 points and is rdy by next turn. The other scout gets 15 points and is already close to halfway done. If the industry points are so many and overlap the ships queued by a large margin; IE 200 points, and you are building 50 20point scouts, then 10 scouts would be built and ready by next turn.

A theroetical screen shot of this production system would be simple and effective, the production screen of the planet would look very simliar to how it is now except that it would have a list of all the projects you have assigned the planet to build. For example if you ordered 2 scouts, 6 cruisers, and 1 transport then the list would show the 9 ships in the list with a progress bat of how far each is to completion. By default production points would be evenly distributed however you can select a project to be the priority, giving it 90% or 100% of all the industry points.

The advantage of this kind of system are 1) manage production a little easier, esp on bigger maps, and 2) by allowing multiple ships to be built on the same turn it helps alleviate the problem of an enemy's fleet sitting on your doorstep with with more numbers killing your individual ships with over whelming firepower.

[Build memory]
Manufactured goods become cheaper as more are built. This is in part due to manufacturing centers tailoring their setups to what they are building. I would see a system such that as a world builds more of a ship then that ship design becomes cheaper to produce on that world. IE for every 5 or 10 scouts you build on a world the scouts become 5% cheaper to build on that world up to a maximum of a 30% discount. Once production of this scout design ceased on the world the discount would fade in 5% increments per week until production started on the same scouts or the discount fades entirely.

[Colonial Exploitation]
This would be a process in which production could be re-directed for a better effect. This has happened in many cases, namely the british colonies of old(south africe, american colonies, india) raw resources and manufactured goods would be sent to england for consumption.

A process similiar could be done in gc2, IE 4 factories are built are mars and a player could have the production points re-directed from mars to earth. This could involve a freighter or any other transportation vehicle. The reasoning is that many planets are <5 in quality making them nearly useless. The ability to send their production to a better planet makes them much more valuable.

An event could go along with this as well, keep the ouput of mars directed to earth long enough and revolts start to turn up on mars. Eventually mars may or may not rebel and form an independent empire.

[Econ Sliders]
I would like to see these removed, instead of sliders you can view an estimated report for your finances at the end of the turn and tailor what you build during the turn to keep your costs in line. If you build a 50 point ship then you have to pay 50 BCs for the production. If you are researching and have 100 research points then the cost of research per turn will be 100 BCs. A view screen to see all estimated costs and income for that turn would be available to keep costs in line.

[Wealth - Consumer Goods]
An idea for unused industry points. Similiar to the wealth option in MOO2 and Civ3. Any world with unused industry(IE not builing anything or having excess with nothing to use it on) would redeem that excess production by applying it towards consumer goods/wealth. You would make a certain amount of credits per industry point depending on factors.

To go along with this, there could be consumer goods starvation. During war very few consumer goods are produced because all the industry is focused on building ships, this creates an increasing demand for these goods. This demand is shown as a multiplier (x2, x3, x4) for how much more consumer goods will be worth if they are built. This multiplier gets bigger as total war production ties up the world industry(to a maximum cap of x10).

Once the war ends or that world stops producing ships then the production points go towards consumer goods again and that world makes a gigantic profit from the multiplier as people rush out to buy goods that haven't been available. The multiplier drops by x1 each turn as long as some industy is producing consumer goods.

[Initial Colony & Civ Capital]
Not much to explain here besides what I already wrote, factories, farms, and labs all upgrade with tech. These should too.

[Employment]
I saw this in the game files and think it should be implemented. Otherwise there is really no point to increasing pop and building farms. Having to need pop to work the factories and labs would be good.

[Constructor Upgrades]
Constructors would definitly benefit from tech upgrades allowing them more than 1 starbase module addon.

[Planet Defenses]
These would primarily be orbiting defenses with no movement. Use hull sizes like starships. Would include armed satellites and orbital rings. These could either be designed and built like ships or some kind of orbital planet improvement that can be upgraded. They would be much cheaper than ships as they dont need a hyperdrive and can hold many more weapons.

[IGBM - Inter Galatic Ballistic Missiles]
A really big missile, lots of them. Around the size of a tiny or small starship hull, packed with a hyperdrive and explosives. Once launched these missiles have to attack something within range or once out of fuel(they get one turn to attack and move) will self destruct.

[Orbital fleets for starbases]
Already discussed and self explanitory

[Minefields]
Built like starbases, and hidden from enemy sensors. Can be upgraded like starbases as well. With better upgrades they get better hiding and damage tech.

Little late, geting out of here. I'll write up more later.

The change is from a single project focus to a multiple project focus. Instead of world concentrating all industry on building a single ship and or planet improvement you have the option of distributing the building process across the board

This can be done already, and that's what the sliders are for. The problem is you have to use the focus buttons, and that's basically a loss of production. Choosing distribution for each planet would be ideal, but I understand that it would be a pain in larger maps. Though with building queues and programmed production and even the resource transferral you mentioned above that problem would be alleviated.
Now, the whole problem IMO is how the economic system (and that's what drives the whole game) is built. The game basically runs on taxes (*weekly* taxes, huh uh    ), and tourism (in times of war, huh uh), and has a fixed pop growth wether there's a mil or 20 bil pop in a planet (sorry, tourists and colonists moving around would have to be deducted from other planets, and they aren't), oh and trades which have their own weirdnesses. Then you have to use that money to buy production and research, which means that if you don't have the money (or if you're focusing on something else!), the workers will be twiddling their thumbs. Is that normal?    A system based on production instead of economy would be simpler.

I think a good addition would be an optional research cap when starting a new game. Basically, setting a level of technology that all races can research up to then no further. Would be useful if you wanted to play a game focused entirely on one kind of technological era.