Not sure if this is a bug or not, but I went into Rhaerun Arms for the first time last night and every door in there was locked.

-Kalos

That's not a bug. And why they are locked is readily available if you talk to the one NPC there. (I think, if not, my apologies).

The one NPC I saw in there only said "Hello".

-Kalos

Oh. Well in that case, he rents out space. To PC's. Depending on the reason the space is rented, it's usually locked, sometimes not, depending on the given renter of that space.