To be honest, the one thing about SE5 putting me off is the illogical planetary construction, as stellar overlord i REALLY have to build buildings 1 by 1 ? Think moo3 did it better (albeit confusing) with zones that had different resources/variables and you just said what kind of zoning you want there. The game would take care of building/upgrading and every zone would get its own city district (important!) but still left you the choice to override specific district building within a specified zone. On the other hand, Distant Worlds does it even worse with no real resource or planet management whatsoever - exception being fuel and taxes.
Sword of the Stars has no planet management beyond population and Sins of a Solar Empire handles a Planet more like a research building with research options (heh).
There was one mod for SEIV that fixed the thing i talk about via districts you build (not buildings with 1 function) but it is no longer maintained.
Ah well, sorry for OT - i am just way underwhelmed from latest 4X games.
That said, a sun or planet would be way larger than any sector in AI War so what you have to see wormholes as is Lagrange points. Places where you ships can warp to a specific other Lagrange point in another sector
If they'd be real wormholes travel time would be infinite.. oh and did i mention that wormholes are theoretical impossible? ;p