*Objects bellow a certain volume should be excluded. No dragging a candy bar behind you.
Why not? I can drag items with low weights/volumes in real life, why not after the cataclysm?
*They should be MUCH more ungainly to drag around than a shopping cart, wheelbarrow or really, anything specifically designed to be pushed/pulled around. Moving an engine around unassisted, that you're not strong enough to lift, is an ordeal.
If we’re going for realism, should also depend on object shape, (can roll a barrrel, for example, but maybe that doesn’t qualify as dragging but rather as pushing), and an item such as an engine should accrue damage.
All that being said, I have extensive experience being what the game would consider over volume and over burdened in an urban setting over long distance and can say for certain that in such scenarios--short of a cart, dolly or sled--it would be LESS exhausting and MUCH faster to simply return for something, rather than drag it. To the point where I feel dragging should really only apply to things that would constitute obstructions
To reiterate my first point, if you’re going to add a dragging mechanic, don’t start trying to decide what the player wants to drag for them, just let them drag anything, as long as they have the strength (might also want some calculation based on weight of puller and pullee, and coefficient of friction, because even with infinite strength, at a certain point I will pull myself towards the object instead of pulling the object towards me…)
And anyway, isn’t this already covered? Many very large objects can be ‘wielded’ (dragged) even if they cannot be placed in inventory…