Has this happened to you? It seems completely random, but Sadok T'Rang is the only NPC that seems to get consistently stuck in the doorway between rooms. He will sometimes go crazy, psychotically jumping back and forth into the ceiling. This can be fixed, thankfully, with a quick nap (just a few rounds so that new enemies don't spawn).

He also has this annoying habit of sometimes opening the door, preventing a safe resting place (enemies sometimes wander around there, and this is before I opened up Marten's passageway, as I don't need more ghost enemies when I'm trading with Sadok).

Also, Sadok (and the T'Rang Youngers teleporting from the spaceship) have this tendency, found nowhere else in the game, where they start out Neutral to the party, but later become Friendly to the party.

I can understand this with Sadok, where he doesn't know the party yet at first, but gradually warms up to them (becoming Friendly) after a while. This seems to be a function of time, as I noticed that Sadok turned from Neutral to Friendly between naps.

The T'Rang Youngers do what they want, spawing out of the Mothership, about to teleport somewhere, sometimes Neutral to the party, sometimes Friendly. Not important, just a quirk that I have noticed.

The game has connected waypoints, like lines on a map,
unless hostiles spot you they dont divert from these predefined paths,
or change to a waypont string thats not connected to their original one.
So there is next to zero chance that the undead from Martens corridors will get to Sadoks lab.

Regarding the door glitch, its caused by the door design,
happens to any monster of appropriate size which can open doors.

I don't think I've ever had enemies wander into Sadok's room, and it's a spot I have rested in a fair amount.

Then again, my traditional resting spot, by Lord Braffit in Arnika, doesn't get enemies wandering in there unless they've previously seen the party.

I can confirm that groups of hostiles like Apuses enter Sadoks lab and interrupt sleep.
They cant open doors, so they almost certainly came in bc Sadok opened the door on his short path out/in.

Not sure about Braffits room, there the waypoints may be connected to the ones on the street and im atm too lazy to look it up.
However if you jump over the front left edge of the basin you can hide behind the pllarthingie and monsters who enter are quite unlikely to spot you,
at least i never got interrupted there during hundreds of rests.

Due to this ridiculous game design, you must sleep for a full 24 hours (3 full 8 hour naps), to hope that vendors have what you want. It takes a very long time to get all that you want from vendors (especially your Bishop(s) wanting all the spellbooks).

The room where Z'Ant resides is completely safe to rest, as there are only 3 exits: The elevator up, the door where you need the pulse pick to open, and the door where you need the T'Rang arm to open. This is my safe resting place, as monsters can't get in there if all the doors are closed. From there, I have to make a mad dash to Sadok's room, so I haven't opened up Marten's passageway yet (I sometimes have to deal with enemies wandering around, and I don't need the ghosts to add to that just yet, until I'm done trading with Sadok.

Enemies can sometimes wander outside Sadok's room, and if Sadok opens the door, it can trigger a battle. I don't need help from Friendlies, especially vendors. Thus, I make sure to clear out all enemies before approaching Sadok's room. I must make a quick-save before talking to him. If he has what I want, great. If not, I reload multiple times until he has what I want.

I don't think that Lord Braffit's area is 100% safe, as there's no door (same with Antone). I remember, a long time ago, that some Savant Orbs wandered into LB's area (they're obnoxiously fast). Thus, in Arnika, I prefer to sleep in an abandoned house with a door.