There's a lot to talk about here:
First off, NERD is an extremely reputable breeder. One of the best actually, so take their advice even if it's slightly conflicting. They should have feed records on your animal.
Second, don't be in an extreme rush to get food in him. It's common for BP's to stonewall you on feeding ESPECIALLY in a new enclosure. So wait a week from your last attempt and then try a live feeder under your supervision, just to get some food down. Most of the injuries caused by live feeding are done so by adult rats which can have some wicked teeth and bites, I wouldnt worry with mice so much but just make sure you supervise. Making the transition to F/T prey can sometimes be a little tricky but alas most animals will eventually do so.
Additional advice is either get the tub up and running OR get a bunch of plastic plants and hides for your current enclosure. Im of the opinion that having too large of an enclosure is a myth and can always be taken care of with more hides or cover. A cluttered enclosure is a good thing with a hatchling.
Good luck.