Those are GREAT pictures (don't stop) & he's obviously settling in quickly because of all your hard work setting up his home. Providing a sense of security makes all the difference for snakes.
As for thawing mice- I recommend using cold (cool) water until the rodent is totally soft (thawed) throughout, & then warm it quickly using the method of your choice (or a combination thereof). Immersion in very warm water (not boiling hot- you don't want to cook it!) for a few minutes works great, & for the extra fussy snake, a blow dryer can put a finishing touch on the external warmth- happy to say none of MY snakes need their rodents blow-dried, but many BPs seem to. I don't imagine this snake's breeder blow-dried his feeders either, but you'll soon find out. I'm betting this snake eats very easily for you.