My last game with India (immortal, tradition, four cities), had me hitting the roof several times, but I managed to stay a float (from time to time getting a negative score of one or two) even though I was declared war by my neighbours pretty much throughout the whole game. This meant that I was quite aware of the supply limit and had it managed through building the required buildings, and planting GG's (I didn't manage to get any wonders giving supply either)I know I’m painting a worst case picture but this actually happened to me before.
And well yeah, my army was quite small but very effective.
So my first few general impression from how WW works has me thinking that you're indeed painting a worst case scenario in your head. I really love the new WW mechanics, it's an truly elegant solution to the problem of abuse by killing hordes of units without losing any yourself (To my experience this was often, and in many situations an easy thing to achieve against the AI.). I think this to be a positive change towards an overall more fun game play.