On easy difficulties. It's really hard to keep warring with more than two major civ on harder difficulties, and it is too hard to win wars vs. direct-war benefit civs.(ex. Zulu, Japan, ...) If you can win wars easily, it's good, of course, but not quite rational stance.
I don't understand what you mean. Yes, a single war with anyone can be hard - but once they're beaten once, you can keep them beaten forever (reduce them to one city, and burn EVERY tile they have). After that, I don't see how you can really consider them a "major" Civ - they will never recover, and if you declare on them every 10 turns, then 10 turns after you've won another free Golden Age. You need to devote maybe 3 or 4 units to ensure the beat-down and prevent their expansion while you use your main army to fight other wars.



That was majorly unfair bullony that happened.