Get some level 45s of different types, a strong ice type ( this is critical ) and your good to go!
no beat the elite four first
You never go to Hoen.
Yes
They are still in the Pokemon league
go to the kanto region
Yes they do I can tell you from experience.
nothing
Yes you do
When you beat the elite four.
no but when you beat red you will beat the game fully (without catching every pokemon) and the elite four will become twice as good as before
beat the elite four.
Yes. To unlock it, you must first beat the Elite Four.