The numbers of LARGE ships - capital ships an titans - is limited the same for all the factions. 

To have more credits than crystals or metal is pretty normal - does not make you crap with resource gain. And TEC have naturally upside when it comes to trade and credit income, so its given.

There is black market window in top right corner, where you can buy/sell metal and crystal for money, in case you did not know. If you happen to have money to burn, but no crystal, just exchange them. I do this all the time,

Anyway, based on your description its not easy to recommend you a faction, all of them can have big fleets, all these big fleets can go down to lot of bombers very quickly. 

I guess you shall go with your aesthetic preference and with what appeals to you the most, when it comes to basic racial characteristics. Do you like turtling or rather prefer playing aggresive? Does taking over enemy ships and planets via mindcontrolling excites you? Do you like ID4 aliens? How about the possibilty of having jumping Starbase, which can move to other planets?

Timmaigh, I found that I get attacked a little early in the game for my liking, and while I want combat I'd rather have time to build up a little BEFORE I get raped by people - I tend to be in a constant state of SOMEONE throwing their fleets at me, and especially in that game I had a problem with the "Solundi" constantly throwing pirates at me before I had time to build up cash to pay them to sod off. 

I am aware of the market, but each time I made purchases it upset the balance of credit/resource (I'm not entirely new to this structure of game). I try often to include a crap-tonne of Flak Frigs but they apparently do chuff all to bombers which is most disappointing.

How fast are you expanding? Like it or not, when you say you want time to "build up", in Sins that is best done building as large a fleet as you can ASAP and colonizing as many planets as possible. So really in the early stage building up involves a fair amount of fighting anyways.

Yeah, I found out how to use asteroid belts yesterday *doh* that really would have helped, you get quite alot for owning those. I normally have very few planets it appears, in the TEC game I had about 7, and then as I managed to push the enemies back I'd bomb it then take it over. It's still a slow process.

I discovered that the HTS (E4X mod version of TEC Rebels) are much preferable with their damage focuses. I almost took over the system before my ally backstabbed me, so I will have a hack at it later.

Yeah, their reworked truce amongst rogues is pretty fun. Rally the neutral militia to your cause to get an early critical mass of ships and take someone out. A task force of ogrovs at you enemy's homeworld 5 minutes into the game is also very fun...

You should try them sometimes, they might actually taste good.