Since I’v read that you are going to implement Immobility and assisting NPC(s), could you add something like a cart in which the NPC(s) carry your immobile character? This would be effected by the strength of the carriers, even getting the immobilized character into the cart would need strength to work.
I really love the idea of an immobile character, but none of the games I played featured real immobility.
Speaking of carrying I’d recommend an agile S&M-ish class that gets a strength boost at low HP and a health regen effect if carrying an immobile character.
My other suggestion is a cap at which the character cannot eat anymore. That cap would be increased as the capacity increases (like an invisible thing at roughly 60 to 80% of the character’s maximum) with the feeder class being be some sort of healer, shoving amounts of food in the victim until fully healed, therefore passing this limit.