Trade ports, raises your income ofc. What i wonder though, is i've heard something about the longer the trade ship have to travel the more you earn? if so is it not smart(if you got space for it)to put one trade port on each planet?
Media hubs, the more media hubs you have the more influance you make? if you have 3 planets, and put 1 media hub at each planet, you will make more influance than having only 1 media hub at 1 of those planets?
Also if its possible to have more than 1 of these structures at one planets, does that give you any advantages? its probably a waste of tactical slots, but just wondering.