nope, sorry, unless the other person is like your brother or something and you're playing from the same house with the same IP
the key you buy can be used as many times as you want, but only one person from different IPs can use it at a time
in other words, it doesn't work if 2 computers are playing the same key at a time.
No, but you can keep changing your name, for each person.
You'll still have the same ID.
shut up duck, you don't know what you're talking about
unless you mean taking turns.