SnG forum is your friend.

I'll try and answer your questions roughly in order.

30 buy-ins is fine as you as you don't tilt, and that you set a level to move back down to 5.5s if things don't go well.

2 games is obviously an insanely small sample size to see if you're a winning player, don't read too much into it until you've done ~300 SnGs.

I'm trying to work out which game is best for me as well. I'm trying cash games but my tournaments instincts to steal the blinds turn me into a laggy maniac.

You might want to get pokertracker and poker ace HUD, especially if you play cash games.

It sounds from this like you struggle with hand reading. IMO, the SnG format requires the least hand reading skill post-flop, and is largely about assigning ranges preflop as the blinds get bigger. This may suit you.

The biggest tip is patience. You could be a winning player but have -10% ROI over 100 SnGs, it is just variance. Post hands, improve, profit.