I don't particularly want it to be all about the military and war. But, IMO, a lot of the games problems and weaknesses come from not having good military, tactical and strategic facilities and abilities.
No argument there.
I personally thing the diplomatic stuff in the game sucks-- its not that I don't like or wouldn't want those features, I just don't think they're implemented very well (although civ4 did a better job than previous versions).
I would rather have some of the options that Civ 3 had - like per turn gold payments - implemented with better AI, they were removed in Civ 4 because of being deemed exploitative basically because the AI could not handle them.
Another thing is that it should be possible to have a minor skirmish, particularly out in the field, or over an unclaimed city, resource or something like that, w/o necessarily meaning you go directly to war. THAT is the kind of thing you're SUPPOSED to negotiate.
I would like more in-between states, yes. I would like, for example, to be able to have "open borders" for moving scout units around, or shipping military through your neighbour's territory to an enemy, without opening borders to a settler-and-defender coming to sit on a space that I was planning on putting a city on in a few turns. I also think it would really add to the game to be able to enforce uneven open borders, perhaps as a condition on a peace deal; if I've just hammered the living daylights out of Montezuma, I should be able to insist on keeping my troops on his ground for a bit without granting him the right to have his troops on my ground.
Another thing I would like to see improved is spycraft-- for example, it would be interesting / useful if spies would occasionally report "intercepted" communications between other civs-- such as overhearing peace talks or a potential alliance negotiation.
I want Civ 2-type spy units back, with more of the abilities they used to have.
Something I think would be an interesting game feature-- the ability to damn rivers to turn them into lakes for irrigation / water / navigation. There would be pros and cons to this of course, but the ability to alter & manipulate the terrain is only partially explored in any of the games.
Being able to dam or redirect rivers would be very cool, yes. All the terrain should be usable and mutable, given enough time and effort.
I've been thinking about roads some more-- perhaps the first roads ought to be implemented "for free" by the game itself-- as you move units between cities, the game could "wear in" the paths most used by the pieces (along the most direct movement-cost-based route).
I don't agree with this one, but then I prefer to get several techs into the tree before you can even build roads, which some Civ 3 mods support.
If you want to get away from war (military) then you need more stuff to spend money on, and ways to manage it.
(..)
Question for you-- what else would / could YOU think of to add that would NOT be strictly military, or else if it is, would lead to more subtle / balanced game-play in not-strictly militaristic terms?
I would be inclined to make military units more effective but also more expensive; go back to having them cost shields/food/happiness from a home city,
as well as having to pay them.
I would strengthen the options for drawing ahead in non-military ways. I would like something that combined the notion of strategic resources with Civ 2-type having to actually build a caravan and deliver it to make a trade; there are definitely huge flaws in the Civ 2 caravan system but they are fixable, and with the "go to point X" command actually working it's not overly much micromanagement. I want spies who can bribe enemy units and even cities. I also want culture that depends entirely on buildings, rather than a slider, I want cultural conversion of enemy cities like in Civ 3 only much easier, and I want any enemy unit that sits on your territory to have a chance, increasing each round, of deserting to you, that is determined by your culture and theirs.
Spies who can bribe are basically a way to translate a strong economy into a victory. That, and better ways of building that economy, and culture that means something, and possibly a rework of how religion works, would all seem to me options for alternative ways to win. (Possibly also corporations, I've not played enough BtS to have a good feel for how they work now.) In a situation where someone who throws all their energy into building an army is leaving themselves way open to cultural conversion, bribery, and so on, the game is stronger in ways other than war.