One can acquire containers via Furnishing which can be placed down, but the owner can't seem to lock any of these (chest, cupboard, armoire, etc). Why not allow people to take such containers to a local locksmith and, for a fee, have it fitted with a working lock and the key to go with it. If you want others to have access to it, have them a copy of your key made. With any key, discretion and responsibility come into play. This also offers people an option to store items safely outside of buying an impenetrable ship just for it to sit around a larder.
Here's another thing; cities have locksmiths, but all of the doors in and out of the subdivision seem to be controlled by some magical force which has no real explanation except it works on the Permissions system so people don't have to worry with keys.
I think it would be a more interesting experience to -have- to use keys and have to use keys for at least some things. In regards to subdivision housing, it's not exactly difficult to get into them, and adding a working lock and key system adds a new element.
Broke off your 200 month long engagement and now they're pissed at you? Good thing you changed the locks immediately after! Now you don't have to come home to an empty house because all your stuff is out on the lawn.
Having keys as a regularly used item not only adds to immersion (heavy breathing), but it also adds an exciting new element to potential theft, especially if say someone were to lift your key, make a copy for themselves, then slip the original back to you. Of course, a good way to safeguard against that is with buying a Serpentine Keyring (shameless artie plug for support), which would actually make them much more useful for more than just shops (which I'm not even sure if they still use keys anymore or have converted to the magic door system).
Thanks for reading.