There's a lot of balance tweaks that could be done but I'm not sure if any of them would really change the basic economy system of this game. Of course improving the AI would help a lot, but I'm skeptical that they'll ever do this. Game AI programming is such a difficult task, which requires a LOT of time and very skilled programmers to do well. Most games have AIs far less sophisticated than the Civ V AI. And there's very few games where the AI can compete with even a moderately skilled human in a fair match.
The AI can
definitely be improved. The main problem with it right now is they went for a fairly elaborate system that is now tripping over itself because they released the game before it was anywhere near finished. The clearest example of this is when the AI will move a unit (e.g. an archer), on flatland,
past your own units (e.g. horsemen). That is not hard to fix - just make units that are already at the front either attack, or move to rough terrain.
I agree the AI will not reach human levels of intelligence (especially if you don't want its turns to take forever). But right now it's dumbfoundingly and unnecessarily bad.
If they nerf gold, that would definitely nerf the ICS approach to the game, since that relies heavily on buying thing with gold to make up for the weak production in most cities. It would hurt the AI even more though- I think deity AIs use gold for making almost all their units and buildings. One time I saw a deity AI produce 3 new units every turn for about 50 turns, which was far more than his total MFG, so he must have been buying them. The human player could adjust buy just buying fewer units, but I thnk the AI would be completely lost.
If you're arguing that nerfing gold wouldn't work, because it would disadvantage the AI... well, that's kind of easy to fix.
If you're just pointing out that the necessary changes are quite extensive, I agree.
Getting rid of the gold for resources trades would slow us down a lot in the early game, but I don't think it would matter at all later, when you have 10+cities working all trading posts, and most of the AIs are at war with you anyway. The balance in the early game seems OK as it is, except for some big randomness issues like ruins and city state quests.
If you mean "the balance in the early game at Civ V deity seems comparable to emperor in Civ IV" I agree. And actually I'm OK with that. I prefer for the AI bonuses to be spread evenly across the game, rather than concentratred at the beginning like in Civ IV.
But I still consider it stupid that the way to do OK is to sell all your stuff to the AI. And again, single player game balance vs AI is not a real argument! First balance the game so it's reasonable; then balance the AI bonuses so it's appropriately challenging. It's silly to base the game mechanics off of the arbitrary numbers that were chosen for AI handicaps.
Making the buildings better- the problem here is, what buildings will you improve? If buildings increase production, then this will increase the unit-spam and map clogging problem. Same problem, indirectly, if you improve the gold buildings or happiness buildings or food buildings- all of those lead to more people, more gold, more units. The only thing you could do is improve the science buildings, so that the game ends faster before you have time to spam units. Already the research buildings are the most powerful (especially libraries and universities, mostly because scientists are so powerful), so I'm not sure they should be improved more, but that's what I would do to improve the unit/map balance. The way things are now, the balance works because players are sort of "tricked" into making buildings which cost a lot but don't do much. As soon as I realized that I could skip 90% of the buildings in this game, that's when I figured out how to make massive gold and armies. The only incentive I have to make a building, is if it has an ROI of giving me more units or better units before the game ends.
Think of the build options abstractly, as investments. Investments A, B, and C get a 20% annual return. Investments D, E, F... get a 5% annual return.
Well duh, you buy A/B/C.
If the returns of D, E, F... were increased to also be 20% (or even just 19%, say) your overall rate of return doesn't change significantly! You just have more options available to you, in order to get that same return. This is true even if the exact returns of those investments is dependent on some varying external circumstances. (Like, maybe D is 2% better if you have lots of grassland.) Yes, that variation will result in a
slight efficiency increase, because in some of the situations, your return will go from 20% to 22% or something like that. But it's not a big deal. (And if you want, all returns could be reduced 1-2% across the board. Then it's the same average return as before, just with more variety.)
In this analogy, A/B/C represent Settlers/Colosseums/Horsemen, or something like that. And to be honest, some things you can build don't even have a positive return at all! There are many build options that could be strengthened without significantly changing the speed at which you progress through the game. (Most such changes would result in you building more buildings but less settlers, and getting approximately the same outputs.)
And of course in Civ V, the returns you can get on the best builds (settlers...) are probably too high, which means all returns would need to be lowered.