Our coach has a locking door over the gravity water fill.
I hate it. I never have the key when I need it. I am seriously considering replacing the lock with a tab-turn latch. Or, perhaps, just removing the door.
Yes, I lock the truck when in town. I have a Ham radio in there that is worth several hundred dollars.
The only time the house is locked is when we will be gone for several days.
The same goes for the barn and shop.
The cap on my well casing can not be locked.
The ATV trailer and the car dolly sit in the pasture with no locks of any kind.
For a while, after reading some of the horror stories on these forums, I used safety wire on all the hair pins on my fifth wheel hitch. Then I realized that due to a slight misalignment of the rails, the pins had to be driven out with a hammer and punch, so securing them was rather silly!