Personaly, I feel that there is no problem with feeding live, so long as you do it responsibly. As in- NO leaving live prey and snake unattended for any length of time, and to feed the snake a proper sized rodent. Yes, I have had an incident where a rat bit my snake while she was constricting it- but there was no damage done, because she was squeezing too hard for the rat to bite down hard.

Do what you've got to or want to do- just be responsible about it.