You don't 'have' to beat him at all. But beat him as many times as you like, it's up to you.
Once
nothing
you can beat red in mt.silver as many times as you want
Red does not reappear after you beat him.
you start the game all over again
to train your Pokemon quick you need to get a exp share by getting a red scale then trading it with mr.pokemons exp share.then give it to your Pokemon and then beat all the gym leaders/red and then beat the elite four a couple of times simple
Yes!
Mr. Pokemon gives it to you after you beat the Pokemon league and red
Once, I think.
The third and last time you fight him is at the Viridian Gym. He is the leader.
After you beat Red, go to Mr. Pokemon and he will give it to you!
He disappears until you beat the Pokemon league again.