No downvote here, but science "allows for" [sic] whatever IS. It's a bit above our pay grade to say what can't be; for all we know, magic might be a black swan [1].
A black swan event is merely the occurrence of a highly improbable event. That says nothing of the event's explicability.
Edit: more accurate to say science cannot explain true magic, if there were such a thing.
We do not know, as of yet, what, nor how many things are fundamental to the universe.
What's the difference between many religious concepts of gods and an extraterrestrial civilization that (at least on our scale) appears immortal, omniscient and all powerful?
Asimov's The Last Question illustrates the point pretty well:
Two major differences:
1. Evidence. Extraterrestrial life is definable and testable. "God" by most definitions is unknowable, and most religious definitions of "god" and his/her/their/its work are contradictory to scientific evidence.
2. Purpose. Nobody has committed genocide in the name of extraterrestrial aliens, but religion has been used to justify all manner of atrocities.
In other words, the first assertion includes everyone, including ALL religious people, and the second premise doesn't follow from the first anyway. Furthermore, the argument doesn't even answer the question between the differences between aliens and deity, because you are focussing on the religious movements and not the omniscient god!
All around, a poor effort.