That's not a mooon.... that's a Space Station!!!
Hehehe... sorry.
Anyway, I do like a lot of the ideas put forward but I have to agree with Schematic's analysis on most of them.
Also, un-colonizable "gas giants" with large gravity wells might mix things up a big more. (And perhaps serve as handy pirate spawn points?)
I do like this idea though, making Gas Giants pirate spawn points. It makes sense: No priority for empires to quickly move in because you cannot colonize it beyond a simple space station in orbit. It has a big Grav Well to slow down traffic = yummy tummy for pirates. It's powerful enough to mask a small orbital base or some such.
It would work for pirates, but they would have to be semi-rare as not to disrupt too much fun with their slightly larger Grav Wells.
Apart from that I'd like to see moons as an additional population and logistics pump. As far as environmental hazards, as long as they aren't too plentiful and break your fleet if you aren't careful I'm all for it. *Thinks of ST:A, shudders*
Speaking on flashy additions and deathstar asteroids: Either make it available to us to add some primitive orbital/planetary defense guns through a planet development button or make us add a little extra firepower on Dead Rocks. It would make sense since there's no other value on it + it has no logistic points. So let us put a few extra guns on it. (Nothing huge or end-game) A couple missile launchers spread out on rocks, a quad gauss cannon (or somesuch) on the actual big center rock and perhaps a built in hangar.
Scale down tactical points to compensate if needed. Regardless, I think we should have some variation. It's nice to do something unique and since dead rocks have no value other than their position, it would be a nice move.