1) Crafting, or achievement grinding of some sort. Helping friends, perhaps some levelling. There's always something to do.
2) Most content. Nothing has bored me after 2 attempts.
3) Not often enough, imo.
4) I play every day, but I know people who do not and they're just as well off as I. It's rather hard to fall behind.
5) Big patches come every 3-4 months or so.

Actual endgame is glamour. I mean if you don't look good, what's the point of even trying? But seriously it's the 8 man savage content.
Housing is fine, there just needs to be more of it.