Let's just say that there are good story reasons why there is no trade, diplomacy, and politics in the single-player. They probably decided to not add in those just for multiplayer. 4X elements, but not a 4x game.
There are very good arguments that territory can snowball into victory with the gold and research advantages that new territory brings. You're not supposed to be able to research everything, but in actuality, it's trivial to do that.
I'm not sure how to fix that though. Maybe overall cutting the research points in half would help. Cutting the territory's research points back to the original 1 for every country would probably be too much, though, at the current prices of 20 and 40 per higher tier upgrade.
I kinda think that well, territory should be useful to own.
If the AI was better at snekaing around and invading your territories with transports that had actual threatening numbers of troops, then you would have to spread your forces thinner and couldn't defend everywhere. Right now the AI usually only hits your front lines, so you can leave huge areas of territory empty or with a token trooper at best.
Last edited by Stabbey; 04/08/13 03:30 PM. Reason: Ai and such