I want to make money and save up on resources as easily as possible, which is why I want to know if you can earn caps for evicting a dweller. I don't have many "useless" dwellers and I don't want to risk sending them out without knowing the "pros and cons".
You don't get caps for evicting a dweller.
However, one key resource saving technique is making sure you do not get attacked by deathclaws. It's 35 dwellers on survival, and 50 on normal.
Keeping your population under that number will save you a lot of caps used on resurrection.