I, personally don't have a great deal of trouble with the idea that God has countless orbs in countless multiverses and their galaxies populated. There is that Scripture about "All Creation groans, yearning desperately for the manifestation of the sons of God." Whatever that means--it sure sounds like a LOT more than this boot/camp Officer's Candidate School for future rulers to rule and reign with Jesus--are waiting for satan, sin and evil to be put down once & for all.
HOWEVER, in terms of the critters reported on visiting earth and dinking with humans--they either do horrid things to their victims (sometimes mutilations without anesthetic exactly like the cattle mutilations); rape; etc. NOT NICE. . . . or . . . they treat humans like a veterinarian treats the calf he's about to butcher for the family reunion--caringly--sort of--to a point.
I personally don't recall any convincing evidence that any of the critters are NOT fallen angels. Evidently they ALL LIE routinely, chronically. And we know who the father of lies is.
I somewhat expect there to be a good-cop/bad-cop scenario with critters playing roles of good and evil fighting each other--whereas all are actually in satan's employee and it will be yet another delusional seduction to result in harm to mankind.
ET treatment of humans is not any worse than human treatment of humans. Assigning demonic characteristics to them because of such behavior is superstitious.