I had access to that building on my alt, Solarim, before I was invited to the alliance (thanks to Tekari!). So anyone has access right now.
Also, there needs to be a tile between the trader and the wall to stop people accessing it through the wall. I tested it out today after reading about it a few weeks back. A fence around that corner would solve the issue, and a lock on the door would solve the strangers coming and going.
I've attached a diagram of how you'd need to place the fence. It'll be a bit ugly, but unfortunately necessary seeing as trader's can't be moved (very annoying, that). The alternative is fencing in the building for a more well-rounded look but a bit more hard work.
That is, if it matters at all lol.
I don't mind doing the fencing, I doubt it'd take much effort, but it'll still be a few days til I move Kaloth up that way.
I also look forward to you coming back when things have settled down, Kiwi
It'll be good to have you around again.