re: Poker & 6 handed or 9 handed???
6 max is more about isolating weak players, while full ring is about beating the weak-tight field. Full ring is a bit more reliant on your actual cards, however, full ring is a much more steady income than 6 max.
I can play 9 tables (the max my site allows) of full ring fairly easily, and just grind up a steady profit. 6-max I prefer to play 4-5 tables max, and the swings are bigger.
And yes, you can play looser when you're playing 6max, but not by a whole lot.