So, the lore says that the Chimer just migrated to Resdayn one day because Boethiah told some guy named Veloth to leave his life in Altmeri society behind (parallels to the myth of Yahwey and Abraham?). Of course, they were also helped out by Azura, who taught them to be mysterious, and Mephala, who taught them to kill their enemies in secret. Boethiah is the central figure in the event however, because he/she rallies the Chimer through Veloth, devours Trinimac when he tries to stop them, and supposedly teaches them their legal sytems and "responsible" architecture. Honestly, I would have guessed Azura to be responsible for that last thing considering the whole gift of mystery, but my real question is this: how do these three daedra fit together? Does Azura like to have her generally benevolent image mixed with those of treacherous Mephala and rebellious Boethiah or does she even care? Why do the Dunmer stil consider these to constitute the three good daedra when it seems something like Azura, Meridia, and Nocturnal would be more appropriate and certainly less controversial? And why, of all the daedra, would Boethiah be interested in architecture? I love Dunmer culture (they're probably my favorite race. It's a close tie with the Bosmer), but their religion is incredibly hard to understand. Someone needs to explain this, please!

You get it backwards. Dunmers don't consider Azura, Boethiah, and Mephala to be good because they are/were good. Reclamations are good because that is how Dunmer categorize them according to their theology. To put it in simple terms, its more about theology and less about straight up good vs evil. Daedra are neither good nor evil to begin with. Meridia can be okay with butchering of a cathedral, and Mehrunes is okay with overthrowing a tyrant.

That is the point, this is their religion, that is their history and interpretation, that doesn't mean that their version aligns perfectly with reality.