Something that usually poses a big problem for me is that by the time I'm building my sixth city, it's just something I use to take up territory space. I only have a core of about five useful cities, the rest don't do anything. Past micromanagement, is there a lot I can do? Assistance is appreciated.
several points...
one, city placement is the biggest thing (IMO). If you place your city in a strategic location, it can make the most out of the surrounding terrain.
two, make the most out of the surrounding terrain. Work the tiles right. Don't irrigate bonus grassland, etc...
three, build the Forbidden Palace ASAP. The sooner you get it built, the sooner you can reap the benefits
four, if you're gunna' spend the money on courthouses, build them early on too (I wouldn't advise building them in the farther out cities, as they're just a waste of money on higher levels)
five, build up population in far-out cities, and make tax-farms or science farms. That way you can have a larger income and research faster, and your corrupt cities aren't going to waste
six, use your core cities to build important units and improvements to conquer far lands
seven, don't ignore the use of an airbase rather than building a money intensive airport. Its an easy way to ship units without spending as much money and effort in far off corrupt cities
I'm sure there are many, many more tips that people can give you, but those are just a few