I will pretty much have too,
no choice or pay a premium to have someone show in the middle of no where, to do work.
Ive seen a ton of off grid guys that can't get subs to show up even when offering a premium just due to their location.
Leaning towards more steel than wood,
thats great. wood sucks long term.
no sheet rock,
thats good. sheet rock is a joke of a product and serves little purpose IMHO (all show - no go).
min 36” doors,
focus on door opening size not door size. you want a minimum of 32" clear opening from jamb to door with the door open @ 90*. thats code minimum. Chapter 4: Entrances, Doors, and Gates - United States Access Board
also IMHO it's a really good idea to get a door that can handle forced entry attacks and is efficient. I know that can sound expensive but a good steel door from a big box store with upgraded hardware like I added to all of mine will usually suffice.
actual safe room Nado rated,
no idea what that rating equates to - but I'd like my cabin to be hurricane rated at minimum with a fema rated tornado room.
green house attached,
thinking of KISS - this is going to be a massive brain drain trying to figure out so I'd have it detached. sure it can be done, but with limited $ and labor should it be? thinking long term humidity/HVAC and pest issues.
In addition to a HVAC system, interested in a passive cooling/heating using earth tubes as well.