Yes, well aware of the rating required as the garage is 4' from the house.
Ended up just going with R-19 faced batt for now. It'll be a huge improvement and when everything is mobile again we can get a drywall lift and/or scaffold (12' ceiling) in and do the dirty work. Then if we're feeling fancy, spray in some cellulose.
Heating - yes. Currently a 220V unit heater but thinking about getting one of those all-in-one diesel heaters for it, if I can find a good spot for the exhaust. I have a propane salamander but always feel like I'm pushing my luck running it in there.
'06 EB 350, Advanced 4x4 (soon to be MG), 6.7 Cummins + Allison, 24" bubble top. Bright yellow. The rumble bee.