yes , masdaamer was talking about sportsbook bets
$500.000 bets are accepted on some of the events ( depending on the odds)
Not after some wins. At stake I can bet 10-25$ on NBA games. haha
your account must have been limited because you were lucky on high stakes bets
it is pretty normal , almost every bookmaker I know does this
otherwise several pro or just very lucky punters would sink the site very fast