re: Poker & Upswing and Short stack tables
Yeah, taking shots is fine when you're nicely over-rolled for the limit you're playing, but not yet rolled for the next IF you really think you can beat that table. That being said, you would probably do better to pay your dues at your proper level and learn what there is to be learned about this complex and nuanced game there.
If you do decide to take a shot, you MUST stop your shot before you dip down too close to your bankroll minimum for the limit you are playing, otherwise you risk that limit winding up below your bankroll, and for taking too much of a shot at a clumsy step forward, you will have take 2 steps backward, or more likely, will persist at the level you just underrolled yourself for and increase your risk of ruin.
Remember, the various buy-in recommendations are based on solid winning players whose risk of ruin is rooted nearly entirely in variance. Even the 20 buy in rule that Ferguson made famous was a rule he set for himself to negate risk of ruin. Unless you think you're as good as Ferguson (you're not, but it's okay, me neither ) you should have more.