No. You can only do it on offense.
Yes, the assistant can call a timeout, players on the court can also call timeouts.
they will give you a penalty
yes. but only on a dead ball. You can't call a defensive time out when the ball is in play.
You can call a timeout whenever you would like to.
No you can't.
Only the head coach or a player on the field may call a timeout legally.
Yes, but not just in Ohio it's like that everywhere including the NBA.
The coach can call a timeout
Anytime the team possesing the ball wants to as long as they have time outs left.
a team can call 20 second timeouts or 1 minute timeouts (full)