my suggestion is simple, allow chests (not crates) and cupboards(maybe) to have locks applied, it would be nice to allow theft on the general area of a claim, im fiddling with fences to do so atm, but directly locking them seems more logical
I'd also like to see lockable containers, but I'd like to note that in your specific case, wouldn't folks be able to just lift your newly locked chests off the claim and take them home and bash them?
Maybe the game could use a "theft-but-not-liftables" permission but I have a feeling it wouldn't be very frequently used.