is there a somewhere that shows the entire alphabet of Celestia in one place?....
Yes. In the game, you can find something called the stone of Mozzorath, which has a pangram (a sentence that contains every letter of the alphabet) in english writing, Grizzleheim writing, and Celestian writing. I have actually already decoded the Celestian script. Once you collect all the pieces, a stone will appear with the different scripts. This quest is available from Balestrom after you complete the final countdown quest.
I was able to decode it by looking at the Stone of Mazzaroth, the mosiac of the worlds of the Spiral in the District of the Stars, and pictures of the Zodiac symbols in the Astral Archives.
