My humble piece of input - units should cost population points as they should and require money/food to maintain.

I am just bambozled with the massive hordes of units that are roaming around without any considerable consequences to your economy/food production/population.

Now, if we are talking about realism, this would be reflective of how wars drain one's society.

Also, when you lose a unit, your society should take a hit (unhappiness like +.025%. Or if they take down a unit, -.025 unhappiness. When you lose a city, you take a big hit or if you win a city, you take a boost in happiness. Makes any sense?

If, you start a war, your pop/treasury and happines to reflect massive drafting. If you are attacked, your hit is much less as you are defending the homeland.

The more advanced and complex your army is, it becomes more expensive.

AHHhhh, I am sorry Houman maybe this is too much to ask and should be reserved for civ5. (This is the part I loved about civ2). I wonder how the AI would handle this?

Units should really have readiness levels - if you allocate less money/food to defense, your units would be in a damaged state (to reflect diminshed strength).

Units with no supply lines/isolated/cities surrounded, should also show diminishing readiness.

This is the one BIG part that I think civ4 sucks at.

Also, if your society should get bonuses for being at peace for x # of years to reflect commercial growth in absence of any wars.