Timer should be two minutes of being grey to everyone, and you're perma to the mark until you die. Poison comes in handy for killing yourself to wipe your perma status, btw. There's nothing more annoying than swiping something great and getting away with it only to run into some guy you stole from two days ago and getting killed and looted.
Snooping (or as I like to call it "shopping") won't reveal you if you succeed. At gm snooping you should rarely fail, making it invaluable. Nothing like stealthing around an entire group and choosing the best item to target when they have no clue you're even there.
If anyone wants to trade tips just pm me- I recently came back after a few years out of the game, but i used to play on dial up, which forced me to get creative in order to survive.