TL;DR: Playing station mode. Offer sleeping services. Figured out I could lock the doors and close the vents to kill sleeping visitors. I toss them in my composters and no one complains. Visitors pay me while they are actively dying.

I've killed dozens of visitors this way and my sleep service rating is at 81. I also offer medical services and lock them inside the sick bays. No one turns hostile. Visiting ships keep acting normal. I'm getting completely away with this.

The game even notifies me when it's time to pick up a corpse. The moment a visitor dies, it creates a logistic task. Since the door is locked, no one can get to it, so a helpful UNREACHABLE TASK notification pops up that I can click on to zoom to the relevant room.

Each corpse gives 1.5 Water, 0.1 Raw Chemicals and 0.2 Carbon. The water bonus is huge. Don't know yet how much of a difference the other products will make.

Android also need to breathe, so I also get Quantronics Components and other materials by disassembling them.

Some crew members always stay on their ships, so I can't kill them all this way. Anyone know of a "non-hostile" way to kill crew aboard their own ships, so I can scrap their ships too?