Ok Ill give this a shot hope this helps

Try a Live Hopper mouse works like a champ
No handeling until he eats 3 meals for you
Move to a quiet room until he eats regularly
The rest you seem to have covered Black out the side correct hides and husbandry. What are you measuring your temps with? I would recomend a Accurite thermometer Wal mart should have them for about $15 looks like this
And feel free to ask lots of quaetions. I would recomend a 10G tank for now smaller would be a lot better for this little guy right now