Speaking of support items, I think there should be at least 2 slots for them. We can lug up to 4 halberds on our back – and equip them instantly, no less – but cannot keep both a bandage and antidote vial on our belt? Plain silly… Make it require a perk if you have to (would make sense to include it into “bags and belts” IMO) but add more slots.
All of the accessories, except for wardogs for obvious reasons, can be put into the bag slots.