Okay, this is probably a silly question.

But, why would the Chimer/Dunmer http://www.imperial-library.info/content/house-troubles http://www.imperial-library.info/content/anticipations?

Aedra and Daedra says this on the subject:

So, the Dunmer believe that they ARE descended from the Daedra? So they would disagree with the http://www.imperial-library.info/content/monomyth?

The Monomyth, possibly mistakenly, lumps both Aedra and Daedra as "ancestors"

Now, I know that the Chimer separated from the Aldmer based on a fundamental difference in ideology. But maybe I'm unclear on what that was.

I know that Azura especially has made her way into some racial origin myths.

Aedra and Daedra says they had a fundamental split in ideology over their mythical genealogy. So, I guess that answers my question? The Chimer believed that the Daedra were their true ancestors? And the Daedra let them believe that? So the Chimer exodus was a big trick prodded on by the Daedra? Or is there anyway that the Daedra COULD have contributed to creating them?

The word "aedra" means ancestor in Altmeri. The Dunmer have different beliefs. You need to bear in mind that the Monomyth was written by Imperials, and so the information it gives about other cultures is being interpreted (or misinterpreted) through a bias.

Aedra and Daedra are aldmeri not altmeri, right? And the Chimer branched off from the Aldmer. But what you're saying is that perhaps I should take the Monomyth with a grain of salt when considering the elvish perspective?

I know that "not our ancestor" is an unreliable translation, but it's still the negative of "ancestor".

"Ancestor" is not literal. It doesn't mean fore-father here. The Eight are the most prominent and important group of Aedra, yet no one is descendant from them. They are the special, because they remained whole. The people of Tamriel can see them orbit Nirn. Yet they are Ancestors.

A more accurare translation would perhaps be Patrons. They are greater spirits worshipped by lesser beings. The relationship is similar to that of Lesser Daedra with their Princes.
It's a "Son/Daughter of" thing. It means "associated with".

Note that the Chimer claim that the Daedra are their "Better Ancestors" os also a wordplay on the Altmer worshipping the "Ancestors of their Betters".