1, you can set the komi as you wish
2, try the F2 key
3, use the "keep quiet" button to disable any communication between spectators and any of the players
4, you can export only after the game finished.

OP

> 1, you can set the komi as you wish

Yes but 

before

 the game. So default komi 0 is used most of time.

ok for other points. Thx