I think its better, instead of personal permissions for every item and personal loot permissions and all that which is mandatory for everyone to follow. LIKE A GODS LAW. instead of these artificial limitations we can make everything for free, but with karma punishment for rules violating.
i give u an example. everyone can loot boss BUT, if you were not in the party who killed this boss and you are just a randome guy who came here just to steal then you get marked as a criminal and everybody can kill you without punishment.
another example. there are wagons in a city. and everyone can leave this wagong there and only them have a permission to move it. this way city will be overcrowded with wagons. instead everyone can move it and take it and use it, but if this person is not a citizen or guild member he can be marked as a criminal and only if he was reported as one. so again - its not a game force you to become a criminal but other player. so if no body sees you you can steal this wagon, no problem.
other example. buildings and crafting stations. everyone can enter and use them. well, not everyone but those who have access to them. by this i mean if door is opened by owner/owners with a key and its open then everyone can enter it and if there is a station inside everyone can use it, but again, if you have no rights to do it then you can be claimed a criminal.
finaliazing. there is a game called Foxhole and there everything is for free. there are no possesions. maximum you can do is to lock your car, but everyone who have tool can open it. and this system has a lots of fun. its very interesting idea. it give people a freedom and you you dont like that your friend or enemy steal your car you can just kill him and take it back. in this game we cannot complitely copy it but partly we can by implementing karma mechanic to it.
to make it easier we can allow gouvernor/shop owner hire guards (not imortal) for marking bad players as criminals, and they will have like a vision feild and they will be patroling area, so you still will be able to steal when out of watch. but its will be difficalt. meanwhile any player can stay in shop and claim stranger. if its a guard of private house then if he will be killed then criminal cannot be reported. so beware.
this idea sort of leads us to lockpicking chests and house doors. which is not too bad either. the main thing is to avoid sort of physical limitations and being treated as children when you sort of hide knifes far to the carbord so they cant reach them.