As you probably know I am not persuaded by the “God-Demons/Angels—Man” template.
McKenna’s simple explanation of why that does not make sense is his story of the little child.
The child sees a beautiful flying creature outside the window and stares in wonder.
Then mom shows up and says “that is a bird” “bird” “bird” “say bird”....
and much of the joy is gone....
Human categories not only can impede knowledge but often can take much of the beauty and joy out of life.
As I said, the Biblical usage of "demon" is probably grossly inadequate. But the consideration of some kind of daimon, faery, quasi-visual spirit being is not remotely related to "demon."
That said, I foreclose no options. As much as the "beings" may be comprised by a vast array of different entities, some of them might be evil in the classical sense.
Yes and no.
We are human and can only begin the process of discovery by iteration between all the creatures (i.e., points of reference) we know without closing our minds and destroying our imaginations.
A person trying to explain a giraffe to someone who has no knowledge of giraffes might say "it's like a horse, but still very different" without killing the joy of discovery. Using "horse" as a starting point establishes a new, if very loose, frame of reference on an old familiar one.
If you described a giraffe as only "like nothing you have ever seen" you haven't ignited an imagination either.