This may not be what you wanted to hear, but that is not beleivibly a space station. who in their right mind would make a space station out of stone? and why all the open spaces? it seems if they wan't to get this into space, they would want the least extra weight possible, there should at least be some possible need for that extra space. and I don't know if you like it, but I think the lightmapping on that first screenie is a little odd. and where is the light coming from? you should put some lightbulb entities or something.
My two person team is currently working on a Space Station at the moment(yes that's right, two people, someone actually doesn't run from me becuase I'm kinda creepy), and if you wan't we could post some screenies for you.
EDIT: one suggestion, go to
http://forum.thegamecreators.com/?m=forum_view&t=95544&b=24
and download the plasma barriers, they look awesome, and they could belivably be on a space station set some time in the future.
NOTHER'EDIT: put some indestructable windows looking out at nothing, and set the sky to scifi\spc
"If it weren't for monsoor here, this town wouldn't be here, and that kid would never grow up to lie about texas!"