Yeah lock picking just needs to be a tool that wears down.
They could have a few tiers of tools in this category.
I like that for both play and simulation reasons.
I've got lockpicks as I teach a class with a week of physical security issues in it. The students get to pick stuff in the lab, as well as use other non-destructive entry tools. I've never broken a lock pick. None of the students have either, and if you're going to break one it will be when you're learning as you'll try to force something.
If we're spit-balling ideas here, I'd suggest treating the "lock pick set" as a mobile workbench, of sorts. It would be one item in your inventory that you could add tools to. There are a variety of lock pick shapes and tension tool sizes. There a shims. Then there are things like under-door tools and traveler's hooks.
If you wanted to go crazy with realism, you'd need the right tool in your kit and then time and maybe training. You cannot, for instance, open a combination lock with a lock pick. I open many "secured" doors as part of my audits via a traveler's hook against an incorrectly installed latch, which is more common than one might think.
To keep it simple, you could just mess with time and, of course, wearing the tools down and having to repair them with a repair kit.
As you say, more advanced tools are possible too, like the "gun" the police use or the newer "Lishi" tools.
They don't really want doors to be possible to unlock because they are intended as a way to direct players along a given path. You can choose to break the door down (or window, wall, etc.) to bypass the path but at that point, it is clear to the player that they are bypassing the path. If you make it possible to unlock locked doors, then it no longer is so obvious that you're bypassing the intended path, especially for a new player who doesn't understand that there is an intended path.
True, they don't want that. As you point out, a locked 1,000 hit point commercial door is not a barrier, but a signal. And, if you spend 30 seconds to 1 minute knocking it down, it's gone. So make picking the lock of a commercial door take 2 minutes -- which by the way would be fast for most folks, unless you're the Lockpicking Lawyer of YouTube fame. Let the bullet proof commercial doors take 3 minutes and require some level of perk/skill. Finally, Don't let any of the "vault" doors be pickable. As for residential wooden doors, well they're made to be destroyed by people who are harvesting brass. You'll find many POIs without residential doors after somebody finds that perk book.
To add to this, I'm finding many POI doors in states of disrepair both to allow zombies to get through them quicker and because the designer didn't want all of the boards and stuff to appear. The doors are kind of being weakened.
