I hardly ever pillage anything. I don't want to destroy something I'm going to own very soon.
I also am one of those people who only build a few cities to start. I'll normally build 3-4 to start, then gear up for war. I go for prime city spots, and don't worry all that much about distance...within reason. But my early cities have to be able to get up and running quickly. I don't want a jungle city that will take ages to clear out, or a city that will need irrigation chained to it, or one that will grow too slowly. I'm looking for high production sites with enough food to work all the mines, or high food sites that I can whip. And of course, the military resources. I'll expand to more than these core cities if there are happy resources I need, or some really juicy spot that I don't want the AI taking.
War economy...whip/chop courthouses. Pay attention to your trade routes...in my current game, by going to war...I cut myself off from all foreign trade routes because they all went through enemy territory. Also look for the Holy Cities that can generate some cash, or Wonders like Great Lighthouse that can really boost your economy.
And no, you shouldn't need 30 troops to go to war. It's no wonder you have to wait so long to start one. But yeah, building wonders and more cities is going to slow that goal down. Just focus on four cities, and no early wonders. The only early wonder I normally build is the GLibrary. It's much more satisfying to capture a city with a wonder than to waste 500+ hammers building it anyway. Make the AI work for you.
