Some ICS feedback so far:
Your gold runs paper thin in the early game, and 42 gold from a goody hut suddenly makes you dance around the living room. Thus, as Solver's review pointed out, even a city maintenance of 1 or 2 gold begins to have significant meaning. I was fortunate enough to setup a silver mine and built roads to it, etc., which has helped.
So, as of now, still early game, I have 4 cities. The 4th city put my gold in a -1 per turn, and I left it that way for a long while (again, the goody huts were key). But as I plan now for the 5th and possibly 6th city, I have had to sacrifice 10% research to stay in the positive. This means, in effect, that I will be running negative again at a -10% research penalty against the AI.
Of course, I am on Noble setting, which means the AI has no bonuses. So in that sense, the situation about sort of means I would be upping my difficulty (for the early game at least). In other words, this is fun again!
Finally, the biggest piece of this puzzle will be how well the AI pushes its tech and gold advantage. But with defense given a boost this time around, and with at least one warrior and one archer in each city already (usually with lots of promotions from killing attacking barbarians), it would take the AI some concerted work against me to put the hurt on. For the moment, then, I'm turtling in order to pump out the maximum number of cities I can possibly sustain in hopes of having a strong mid to late game.