Thanx 3 confirmation enough?
As far as I know it is impossible to cancel or reverse the bitcoin transactions once it gets confirmed and fort that even one confirmation is enough so no need to worry about the number of confirmations.
I think so too, once a confirmation is done it means transaction has been processed and in fact, you can see the amount of coins sent already. So I don't think cancellation is possible then.
Cancellation of a transactions only occurs when the paid fee is too low and its in the pool for too long like months then it might get cancelled but when we had one then its completely done even many gambling sites need one confirmations as well.