One Time Passcode is required upon account creation. You will be prompted to verify your Mobile Number in order to log into your account once you have submitted the Open Account Form. You will not be able to log into your account until you have verified your mobile number with a One Time Passcode.
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.