1) I would be more concerned if it wasn't hot. Hot is a relitive term. You can only hold your finger on about 130 deg. f.
2) The click is just the crank going over TDC. Don't worry unless it clunks.
3) The 90 is a ringed engine and the 50 is ABC or N. The 90 will not produce its full compression unless running.

Quit worrying and go fly.