Tigerbeat,

The single most important factor when considering a push with 8BBs or less is not your cards, but your "first in vigorish."

To put it more colloquially -- You MUST be the first one into the pot to have the best expected returns on your short-stack push.

Therefore hands 1 and 3 were bad pushes. The rest are fine.

edit -- First In Vigorish trumps even your cards. I would rather push 800 with a 72o with three folds in front of me than push that same amount into a 3xBB raiser in front when I'm holding ATo