Interesting topic, to say the least.
As far as canon, my interpretation is that canon is that which was aired on television (i.e., not the telemovies).
My understanding of the Beings of Light, Iblis, Angels, and Satan are intertwined with the central figure being God.
As the story is told, both the Colonials as well as the inhabitants of Earth, sprung from a mother race which inhabitated the planet, Kobol. They would have had a common belief system and set of values. They would have had a religious belief system which may have been the same for all the various peoples or there may have been multiple religions, as there are on Earth, today.
At any rate, there would have been numerous similarities amongst the peoples that made up what later became the 13 tribes of Kobol. Much of that belief system would have survived the early centuries following the Exodus from Kobol. In my opinion, a greater amount of the original Kobollian standards would have remained intact throughout the Colonies, as opposed to on Earth simply due to greater opportunities for reinforcement of those beliefs by the sheer number of people from the 12 tribes compared to the number of people in the 13th tribe.
Additionally, the tribes which later made up the Colonies may have actually been able to take physical (and tangible) artifacts from Kobol whereas the 13th tribe may not have been able to do this. (I'd consider that to be conjecture, though, since it was never covered by the show.)
So, where does this leave us?
Well, as I mentioned, above, God is the central figure for the 12 tribes and for the 13th tribe.
I would consider the Beings of Light to be similar to Angels because they represent a level of existence that is rooted in corporeal existence, i.e., flesh and blood like us and like the Colonials. According to canon, the B.O.L. answered Starbuck's question (who are you?) with the phrase, "what you are now, we once were; what we are now, you may become". Similarly, on Earth, angels are thought to have been, at one time, 'flesh and blood' like us.
How one ascends to their level of existence, is not known.
I would consider Iblis and Satan to be the same being. Accoring to show canon, Iblis was once "like us" (a Being of Light) but, chose to use his power for evil and was 'cast out'. According to the Bible, Satan was cast out of Heaven for rebelling against God. In my mind, the person was the same, the casting out was the same event but, it was simply portrayed (or recorded) differently by the Colonials and by the people of Earth.
