Yes, Bet365 is safe to use. The sportsbook provides various levels of firewall and other protections and the sportsbook itself is regulated by each of the state gaming regulations Bet365 is legal in.
The funds will be credited to you within 24 hours of your withdrawal request. You can request a withdrawal via the Account Menu ; select Bank then Withdraw. If you have deposited funds via a my paysafecard account, you can withdraw via Wire Transfer.