He's way too old to be eating pinkies. How much does he weigh? My guy is around the same age and he's 500 grams now, and eats small adult rats. Depending on his size (which Im assuming he's a little small - I would by-pass the fuzzie stage and get him on rat pups ASAP. At his age you couldn't over feed him with pinkies.

Sometimes BP just are not very good at getting headshots, and swallowing their food isn't a fast and easy process. It can take my guy in excess of ten minutes to swallow his rat but as long as your feeding him around the thickness of his belly or 10 - 15% of his body weight, he'll get it in. Its what snakes do.

As for feeding location, feed where he'll take. I feed right in his enclosure. I know some people are against it for various reasons but I have never had a problem and he's never refused a meal that was inside his terrarium, and he always refuses when we try the feed box.

In conclusion, feed him bigger meals. He will eat it - you just have to leave him alone for a bit and he will swallow it. At his age he should be at least 450grams.