Considering that most, if not all forts, caves, ruins and/or other things outside of towns tend to have respawning enemies, and containers that love to remove things that you put in them, it really makes for a bit of constriction on what I'd like to do. WHat If I want to be a Necromancer and set up in one of these forts, make me some thralls, set up a li'l coven and such.

Can I hold a fort for myself?

If you're on the PC you can. However it's not possible with a console I'm afraid.

Some may never respawn however, and might be safe. Check the wiki.

There is a fort that doesn't respawn I believe.

Cracked Tusk Keep. Yep, it doesn't.

http://www.uesp.net/wiki/Skyrim:Cracked_Tusk_Keep

what might the console commands be for removing respawning on containers?

The Thalmor at Northwatch Keep are permanently gone after you completed all the quests associated with it, so you might use that one as a fort.
Not sure if the chests in there are safe, though.