If he's scared of big prey, why would you buy the biggest rats you can find?? Maybe you should try smaller meals, feeding a couple at a time.

As far as I'm concerned, there's absolutely nothing wrong with feeding in the enclosure. The old "he'll associate your hand with food and bite you when you try to handle him" is just a myth, as far as I've been able to tell. I've fed my guy in his enclosure from day 1 (too much stress on him to be moved to a separate container, I didn't want to put him off feed once he started eating for me) and have never, ever had a problem.

Try waiting until he's in a hide and running the rat back and forth across the door until he strikes, this has worked wonders for me. This is pretty much the only way I feed my guy now, it's so easy on both of us.

I have a question though... are you thinking about selling/trading your guy because he's a difficult eater? If that's the case, you probably should have thought about that before choosing a BP, as they are notorious for being picky eaters... it's not his fault. What are your temps? Do you try to feed when the lights are off? Have you considered switching to a UTH instead of a light for heat? Just some things to consider...