I see your point, but I do know that none of it, besides the envoy cruisers, is in Diplomacy (I was in the beta and the expansions release date is.....already released for some, February 9th for everyone else as I understand it). I do like the surface-to-space weapons idea, it kinda reminds me of when I played SW: EaW, with the ion cannon and hypervelocity gun.
If there was something I feel that there's missing from Sins, it's the use of planets that I take when I'm on the offensive, besides a few for producing ships on the front line. I'm not wanting to be defensive, but I'm moving quickly enough that I don't exactly need any economic growth either. They are just.....there, hardly anything more. I hope they put more stuff to do planet/gravity-well wise in the next expansion (not micro, they are done with those) or the hopeful sequel.