Surprised nobody pointed this out yet, but a rat under 5 weeks old (around 40-60g) is much safer to feed than an adult mouse. At this young age the rat doesn't really understand and can't really sense danger. It hasn't been around long enough to develop the kind of aggression that results in a snake getting mauled.
Now if you're getting up into a regular pet store sized rat - that is more dangerous but you just need to observe the feeding and keep something like a pencil around to let the rat bite down on if it's free enough to bend its head down. Usually the snake constricts it right around the neck so it can't actually bend its head enough to get at the snake.
If you're really worried, take the plunge and convert to F/T.