If the husbandry is right (from what you listed it seemed to be) then I would think your bp is either stressed, or needs to feed live until its established in its new home. I've had to do the later, and switch the picky bp after a few weeks of feeding on live in his new surroundings.
You could try to fill (yes fill) the ground area with crumpled newspaper to see if it helps to make your bp feel more secure. This has worked for me in the past.
About your bp getting 'super defensive', I wouldnt worry about it to much at this point. Young bps can get defensive sometimes. As you handle it, it will learn there is nothing to get defensive about. I had a pastel that would have a panic attack whenever it would be handled. I handled him more often and he quickly grew out of it lol