One of the big problems I am having with the game is trying to figure out exactly what I can afford to build in terms of units (and, to a much lesser extent, buildings). This is partly because resources are not subtracted from your stockpile until a unit actually begins building. This means that you can put 5 units in a build queue but only the resources for the first are subtracted, the resources for the others are not subtracted until they actually begin building.
Given that you have multiple building queues operating at one time, and they all use different mixes of resources, it becomes very tiresome and difficult to keep trying to estimate exactly what you can afford to build, especially when it comes to unit upkeep. In fact, to do it properly, you would constantly need to keep a calculator on hand, and this is supposed to be a game, not an exercise in arithmetic.
So the first thing that I think needs to be done is that resources should be deducted from the resource totals whenever you queue a new unit for construction, not just when it starts building. The game does this, for example, when you place a "sell" order in the market, subtracting the total you want to sell so you don't accidentally use those resources, so why not follow the same principle for unit construction?
More broadly, however, I don't think even this is adequate, because as I noted earlier, it still wouldn't give you a readout of the daily upkeep of all the units you are constructing. So I think what is probably needed is some sort of "master window" showing all of your current builds, along with the total resources they are going to cost to build and the total upkeep they are going to require. That way, you could manage your military buildup in a far more efficient manner, and not be constantly worrying that perhaps you are building too many units or not enough.
And finally, while we're on the subject of overview windows, why the heck isn't there a window you can go to which gives you a full breakdown of what your army currently consists of? All there seems to be is the window that opens from your flag at the top of the screen that gives you the total number of troops. One needs a breakdown of the types of troops one has built, in order to figure out what you might need more of. Yes, you can run around the map counting everything, but again, that is a crashing bore and the antithesis of what a gaming experience is supposed to be about.
So there's a couple of things I would like to see in the game which would provide an immediate improvement in the game experience as well as giving the player a more immersive experience and a stronger sense of control over his empire.