OK...Yes, there is a risk in feeding live. It may not be as large a risk as some make it sound, but it is present, none the less. There are benefits to feeding either F/T or live, depending upon your needs at the moment. I prefer to feed F/T whenever possible. The risk of transmitting parasites is decreased. There is no chance of a snake being bitten by a F/T mouse. But most importantly, frozen mice are less expensive, especially for those keepers that are feeding more than just a couple of snakes.
However, there are some reasons why I would feed live on occasion. Most often, it is for the occasional snake that has gone off F/T temporarily. Most often, it is a breeder female that is recovering from egg laying that needs to eat, but just doesn't want F/T. It happens sometimes. The next usual circumstances where I would feed live, or more usually "kicking just a bit", is when I'm either low on F/T or have just gone through my rodent colonies and collected feeders on feeding day and it's easier for me to just go ahead and feed instead of going through the extra time needed to bag those up and take frozen out and thaw them.
Feeding live is fine, IMO, as long as the snake is being monitored during the feeding and eating process. The big problems occur when the live mouse or rat is just thrown in with the snake and the snake isn't looked at again for a day or so.
And as a side note, even small bites can become fatal...and they don't have to be caused by a mouse or rat. I had a female develop an abscess after the male bit her during mating. The occasional "love bite" happens with no ill effects, but this one was different. It took awhile for the abscess to develop, remaining small for most of the period the female was gravid. And because she was gravid, the vet didn't want to put her on any antibiotics for fear of causing a problem. She continued to eat and behave normally until she laid her eggs. She was given 10 days after laying to eat a couple of meals and build up some weight, even though she was still in fairly good condition after laying. The abscess was then lanced, the wound flushed and she was put on Baytril injections every 3 days. The wound seemed to be healing and she had a second post-laying shed and seemed to be doing well. However, she then stopped eating and the abscess returned just to the side of the original wound. Back to the vet, the new abscess was lanced and a sample taken for a culture and sensitivity. However, she died over-night so I canceled the $100 test before it was sent out.