So, I go into the Seraph again today and find 4 of the doors locked. Nobody's up there but me. Am I allowed to pick the doors so that other people can use them? Only one of them is unpickable.
If not, I'll leave them alone, but if so, I'd rather unlock them for people who are actually online to use. I would think the general rule of thumb is 'Free to unlock if nobody's online or has been online in them for a while, but otherwise respect privacy'.
~BR
Please see if there's a DM online who can go topside and unlock the doors. Otherwise, yes, if nobody's in the upstairs area then you may pick the lock to open the room.
I won't go into a rant about people logging out in locked inn rooms.

One possibility we could do is to have an on-exit where if the area is empty, the doors unlock.
FWIW, if you can see the inside, you can dimension door in and then unlock it.
Please don't do that. DDing into rooms is not a precedent we wish to encourage.
Technically the spell shouldn't even work that way, but NWN doesn't recognize doors or placeables as blocking LOS.
Also, the inn rooms are dimension door locked.