So I am in a predicament...

[anagogy]

So riddle me this: What is the worst these beings can do in their etheric projections? Can they feasibly kill me?

Only with your cooperation.

They cannot create your reality for you. They can only wait for your thoughts to dip into their vibrational range, where they can communicate and influence you, and get *you* to create a reality, with the thoughts you habitually think, where you are going crazy, or about to kill yourself, or hurt others etc.

Again, as Austin said, only through pre-existing distortions. They try to get you to dream a bad dream.