I think your first, and most apparent problem, is that you're starting off trying to write an epic about amazing and unique characters doing amazing and unique things.
That's really hard to do right out of the gate with fanfic. So you should probably go back to ground zero. Write a simple fic about a character that you like, doing something that you think is interesting.
The point of fanfic is not to create an interesting, amazing, all powerful character; but to use characters that already exist, in a way that compliments their existing character.
If you want to write a story about a god in pony form, why not start with something simple about Celestia? Focus on her as a character. Explain how you see her in prose.
You'll find people that want to know more about your take on Celestia. Then it's easier to get people to help with the mechanical side of things. Your commas, word choice, spelling... All of them are secondary to having an idea that lots of people can understand and support.