Thanks to everyone who has taken the time to reply.

I'll definitely keep the 30x buy-in rule, but will probably relax/eliminate the others. In the beginning, I probably will leave a table any time I've made significant forward progress, but with the intent of learning to leave based on table conditions, and not just leaving because I happen to have made some money and am afraid to lose it.

If I do lose, I'll probably post some hand histories and try to figure out what I did wrong before immediately re-buying... at least until what I think I did wrong starts to match the comments I get in the hand histories forum...

Anyway, thanks again for all the feedback.