1) To unlock the $600 bonus you have to play a lot of hands. He'll be paying at least $600 in rake during that time.
That's very hard to do with only $60. If every hand you play is a raked hand ($1 pot or more) and rake is 5%, that's $12,000 of bets he'll have to make. And there's no way a $60 roll can average $1 per pot at first without being waaaay under-rolled.
2) If you transfer money to someone the poker sites
require that the person plays with the money before he withdraws. So if Mr. X transfers $550 to Mr. Y, Mr. Y will either have to have an additional $550 in his account or make $550 in wagers (maybe more?) before he can make a $550 withdrawal.