Sandbox doesn't have to mean full loot and those stuff, you can still do some restriction. Eve for example have both safe and no safe zones and yes if your ship blows up it really does blows up, but if you have insurance on it you will get lots of money back + the clone if your character dies, so you can still do sandbox with a lot of restriction to make it fun.
Lets say that if you die in Fallout you would have x% of dropping loot in your inventory, it svcks if you die, but you may keep some stuff... its a real kick in the balls to loose everything -.-' even if its realistic it's not fun.
Areas around some towns can be safer than others, like if someone kills you unprovokely near a town he will drop status and the guards will dislike him a bit more.. and more until the pker gets totally banned from the town :/ And if you wish to haul many things to another town, then get some protection
But I understand what you are saying :/ A full sandbox game ain't so extremely funny due to that there are some assholes out there that are good at ruining it for others, hence failsafes needs to be created, it may ruin a bit of the sandbox BUT the game will turn out to be more fun to play