Hello everyone, this is my first post on these forums and i only bought the game yesterday (although I have played it at a friend's place before), and after a few hours I have a few little suggestions/niggles to relay to the developers/community.
Number 1: Stars - this is purely a cosmetic thing, but I have noticed that stars do not rotate in game. This is scientifically incorrect - stars do rotate like planets. This obviosuly isn't a massive issue, but I get that voice at the back of my mind saying "tsk, tsk" whenever i go up close to a star 
Number 2: Minor bug - on sending a scout ship to a Pirate base and having it promptly destroyed, I hung around there for a while to watch the fog of war swallow up the pirates. Only it didn't - for the rest of the game, whenever I zoomed in to that base I could see the the green lights of the pirate ships (no geometry, just the lights) floating around and occasionally moving when I assume another ship entered the gravity well. Again, a minor thing, but i thought I should point it out. Sorry if this has already been done.
Number 3: Gameplay revision - whether this or something similar will come in one of the downlaodable expansions I don't know, but I have a suggestion concerning planet subjugation. As opposed to simply nuking the crap out of an enemy planet, I think it would be more interesting to have an invasion force land and conquer on the ground. This would act similarly to the colony frigate - one would have multiple inasion ships of some kind (frigate or maybe crusier - more ships means faster conquest) that could perform theri action on the planet. This would be slower than an orbital bombardment, but afterwards the planet would retain whatever improvements were made by the previous owner, and perhaps some of the orbital structures. The player might also recieve loot collected by the army. The clsoer a planet it culture wise to you empire, the faster and less costly the invasion.
This also acts as a drag for an assault fleet, as they have to defend the invasion fleet, and if an enemy attacks a world acting as a staging area they could focus their attacks on your invasion fleet to slow down your expansion. I am NOT suggesting that the player should have control over the invasion, but just that it would make an interesting automated alternative to bombardment.