I need some help!

I'm trying to make an game scenario totally independent of the actually game. I'd like to make it to where the player character cannot use weapons/magic/fists.

Because this scenario will exist independent of the game, solutions that would otherwise break the actual game are welcome.

Thanks!

Force equip null-magic, maybe?

I can't remember if it need SKSE, but you could use "OnMenuClose" for Favourites, Magic and Inventory to force-equip a no-effect "On-Self" Magic Spell; it'd unequip weapons and other spells, and even though the player could cast this new spell, it'd do nothing.

That's certainly an option, CDM_

I'm wondering though if there's a state or command built in that copies the game opening scenario when the player character's hands are tied... or anything to that effect.

Hmm, You could try DisablePlayerControls. I'm not sure of all the flags, but one of them might be no-combat?