I'm not a vet in CF as well, but like you, a vet in muds in general :)

1. I'd say that 50 hours is enough to hero anyone if you aim for it. Certain combos can do it under 20 hours if they're in a hurry. If you're not in a hurry and take your time, I'd say 100-150 hours is pretty typical.

2. Lots of other path thieves around. Doesn't seem to be true.

3. Dioxide's and wiki there is nice. The official site has some nice info as well, but it's less detailed (less misinfo as well though).

4. Welcome to the club, we are all like that, tempered in 20 yeas of scumbaggery. Most of PK killing involves mobs and your obvious mistakes, so the answer would be "don't do obvious mistakes when something is fishy". The easiest way to get yourself PKed out of PK range, is getting a criminal warrant. You may also get your enemies spelled up, assisting mobs summoned, that sort of things. It's pretty typical and if you're a veteran scumbag, it's not something you're not prepared for.

P.S. Just bear in mind that if you play scumbag, you'll be target to full looting and griefing as well. I'll be first in line ;)