I've seen the umbra but It's pathfinder, which isn't core.
That dirt it taking less room than I thought, that is great
I was planning on getting leadership with a crafting wizard cohort (more spells known) to get a cloak of darkness possibly (casts darkness within the cloak).
I don't have extend spell. But I think the things can work out. I've been told there is a town I've never been too that is close enough. I've also thought of a bag of dirt (my idea was a backpack that I lugged around, that would fall when I'd turn into a gas, I'd create a few more of those and give them to my cohort or trustworthy party members.
The rest thing I don't know, I'm assuming it'll be the same as a normal pcs not getting rest.
The feeding he said "I don't wanna figure out what happens if you don't do it, just keep yourself fed".