[CORed]

If anything, I think you need to discount the equity numbers from PokerStove. They are based on the assumption that everybody stays to the river, which is obviously not the way you play, and probably not how your opponents play either (but if they don't play closer to this than you, you need to work on game selection). For example, your equity with 22 inludes hands won by making a set on the river. In real play, you're probably not going to stay in for very many of those. The question you should be asking is not, "How much lower than break-even equity can I go", but "How much more than break-even equity do I need". I don't have an exact answer for you. Showdown simulations are a useful tool for comparing relative hand values, but they don't come close to telling the whole story.