Is there a point to placing people in the vault storage rooms? Does it do anything at all?

Nope. Let the Empty Room Rats have it. The room doesn't need people in it to store your stuff.

Only when you want to upgrade a room (say, a power generator to a nuke plant) and you don't want them breeding.

I built a 3-room storage room right behind the vault door and upgraded it to the max. I then put 6 "soldiers" in it with big guns and they serve as guards against raiders. They kill them within 6 seconds. I don't have any dwellers in the vault door room itself.

I had wondered how that would work out. Sounds like it does work, and awesomely!

Seems... wasteful. Two with your best guns and stimpak attention during the shootout is enough. Just have the door guards give chase to any who make it past them in the door room.

The only real advantage for having people permanently assigned to your Storage Rooms is that there are always dwellers on hand in case of a random incident taking place in the room. You don't have to drop everything to move people from other rooms to the empty one to prevent the incident from spreading.

I keep all my storage at the very bottom of the vault and just let the fires and rad-roaches have their way. The rooms aren't connected to any rooms with dwellers so the negative events just spread and burn themselves out with no negative effects.

Smart. I thought about building an elevator all the way to the bottom and doing that.

I think RADROACHES are more likely to invade empty rooms.

Or just ho with the best option.

Get rid of the first housing and build a 3 slot powerplant with max S guards in it.

Dont upgrade the door since it will take longer to get rid of the annoying raiders.