Then your general sentiment is that it is too detailed, it doesn't allow every city to become a powerhouse (you can optimize for production...), there are non-war ways to win (I'm assuming you miss religion), I don't understand the point of tech trading with AIs, and playing against AI where your relationship is fluid and ever changing is no fun?
Does not compute.
Too detailed? It's not detailed enough. There is no supporting fire, suppression, unit histories, entrenchment, or any of a dozen features that made PG such a slick system. And yet the game forces you to warmonger. Are there non war ways to win? I haven't come close to any other form of victory besides domination or the time running out in Civ5.
Yes I expect every city should at least have the opportunity to become a powerhouse. Deciding what to build next was for me the most enjoyable part of Civ 2-4. With 16 cities producing something new on average every 4 turns meant I would get to make on average 4 decisions per turn - enough to break up the monotony of moving units without bogging down with too many clicks.
Now with an average of 6 cities producing something every 20 turns my games now resemble:
Nothing to do, click next turn button
Nothing to do, click next turn button
Nothing to do, click next turn button
Nothing to do, click next turn button
Nothing to do, click next turn button
Nothing to do, click next turn button
Nothing to do, click next turn button
Something to do, Finally!
Nothing to do, click next turn button
Nothing to do, click next turn button
Nothing to do, click next turn button
You assume incorrectly - as implemented in Civ 4 the missionary spam wasn't fun.
The point of trading tech with the AI was to compensate for the weakness of the AI and make late era warmongering challenging by giving weaker civs the ability to mount some resistance. Steamrolling musketmen with modern armor was as boring as hell in Civ4 and it's boring as hell in civ5. The difference being civ 4 had an option which let you do something about it.
Changing relationships is desirable. What isn't is the complete unpredictability of those changes. I don't mean I want the +/-1 garbage of Civ4 but if I go to war at Ghandi's request to save him against a third party, I liberate his cities for him and go on to beat back the invading army, I reasonably expect him to behave like a real leader and be greatfull for at least a few turns instead of immediately stabbing me in the back while we're still fighting the first war. If I wanted that I'd play MP.