- accepts vpn
Most the casinos or sportsbooks support the use of bitcoin even the altcoins but the accepts of VPN depends on their terms and condition they just want to avoid having an abuse with their system so I guess its users the responsibility too that the user must need to read this.
Do they block if you win too much?
As long as you comply with the rules and didn't abuse their current system or the account itself not having a suspicious activity you don't need to worry about too much.