Lol-there's no guru's on here bud. Spruce is the most helpful though.
1-yes
2-if you want to close the doors you'll have to exhaust somehow. I tried it today, closing the door while the boiler was firing. Got about 20 minutes of hot. I assume before the oxygen ran out. Opened the door again, toasty straight away.
3-no idea what that hose is but you will probably need a hose that is heat rated.
4-I'm still experimenting. started week 3 on original 2 'd' batteries. Sparky mate of mine said a 12v can be stepped down to 3v but he reckons it'll be easier to just change the batteries, he reckons theyll go for 6 months isn...