Welcome to the site!

Hopefully I can answer most of your questions. First, it is perfectly normal for them to sit in their hide for a couple of days after a meal. Digestion takes a lot of energy from them, so it's also a good idea not to mess with them for a couple of days after a meal.

It sounds like your temps are much too cool. If the cool side is at 70, he will probably get a respiratory infection some time in the future. The temps should be in the low 80s on the cool side and the low 90s on the warm side. Also, it's a good idea to provide a hide on each side so they can feel secure while thermoregulating.

Finally, I wouldn't be too concerned about the wood shaving. It will either dislodge eventually, or he may end up swallowing it and he can easily digest it. If it was a large piece or if it looked pretty thick/sharp, I would suggest trying to remove it, but if not just let it be. You mentioned that you placed him in another box to feed. This can often stress them out and you might be better off and get a better feeding response if you feed him in his cage. Being that you're feeding frozen/thawed you can use tongs to dangle it an inch or two in front of his face and he should stike and eat it.

I hope that answered most of your questions.