I know that there's a way to kill your dwellers. If they die in a disaster. You can revive them or let them remain dead. After 24 hours they will disappear.
But this may have some negative side effects as your other dwellers will be sad about the dead people lying around.
So my main question is, what is the best way to kill your dwellers.
Background: You only can have 200 dwellers in your vault and a waiting queue of about 10 dwellers waiting at your vault door. If the wait queue is full you won't be able to open lunch boxes anymore. This will prevent me from opening my lunch boxes.
If I reached those limits, I need to kill my bad dwellers. Which is the most efficient method? Should I rush a room until rad roaches occur and kill my bad dwellers without any weapons and need to wait 24 hours and loose happiness? Is it better to send them to the wastelands without weapons and let them die? Will this also reduce the vault happiness too?