May I ask why? It seems to me that you're looking into it as some kind of good vs evil deal and that's just not the case... Depending on who you ask (Altmer) Akatosh (Auri-el) the chief patron of the Nine (Eight) divines, probably wants the world to end and all the elves to return to "normal" not-lives.
Vigilantes of Stendarr attack and hate all Daedra worshippers, including those that worship Azura or Meridia. How offensive this is to Khajiit, Dunmer and Orcs seems hardly relevant to them.
I'm sure some of the others have "evil" sides as well...
Of course I could be entirely wrong in why you feel that way, if so please enlighten me.
No, I don't not look at this as good vs evil, that is just not in my characters nature, in fact, its not even in my nature. My method of RP is making decisions which I would make my self, like Azura's star. I think Azura's a [censored] even though she is depicted as being "good", as subjective as that term is. But this played no part in me choosing to get the black star over the purified version. Even though I see myself as a "good" person, I saw that I gain much more benefit from getting the black star, others who roleplay virtually good characters wouldn't take it.
Similar to Dagon and co., they may be seen as "evil" characters, but that has no effect on whether I do the quest for them or not. I do not see it from the point of view of doing a bad deed, but doing a deed which benefits me and gives me a powerful artifect which I can then use to furthur my own agenda, even though the Daedric Princes want me to furthur their own.
Even after saying that, I do have a set of morals, as surprising as that may be to even myself, so I do not use the Ebony Blade that Maphela gave me, not because it is seen as "evil", but because I value my friendships more. Believe me when I say if using the Ebony Blade benefitted me more then my friendships then i would use it, as "eveil" as that would look to other players.
Whether or not Akatosh wish to destroy the world does not bother, I would not go out of my way to try and stop something which I cannot, it is futile. Similar with Stendarr, even though I think it's more to do with his/her worshippers hate of the daedra then his/her own personal hate of the daedra which is driving them does not bother me. They can send all the Stendarr zealots they want and I would destroy them all, I agree that their obessesion is insulting to the Khajit, Dunmer and Orcs, but all they can do is get on with it. There's not that manay Stendarr Zealots in the world to wipe them out anyway.
On Meridia it is not because she is good I like her, I know that she can be a bit of a dike just talking to her, but her cause is what gets to me I guess, plus she gave me a cool sword which is actually useful. All joking aside the reason I choose to weild Meriadia's artifect willing unlike the other Daedric Princes is because of the distaste I have for the undead. It is not because the undead are "evil", I know that some are just guarding ancient tombs in the case of Dragur and Skeletons, unwilling most of the time, but it is unatural for the undead to walk the earth, they must be allowed to go to Sovenguard and rest after the long years they spent down there, they may get in the way of missions a lot of the time, but I know why and by killing them, I am releasing them.
Good and evil is subjective, to me I am more of a neutral.