This may have absolutely no direct bearing on any existing Lore but game mechanics kind of support the idea. So do some aspects of the lore.

Considering that Daedra effectively act like Demons in TES(though there is certainly more to them than that!), would there be some kind of excorcism that could be enacted to banish daedra back to their plane or the waters of Oblivion? Or more interestingly, some kind of object so that Daedra would effectively be killed in the sense that they could not return to do harm in Oblivion or Nirn because they were bound to an object."? Something similar to a Dykkun box. (Yes I just watched The Possession. It was horrible but it sparked the idea.) i know there are soul bindings in TES but could a group have gotten together to soul trap as many Daedra as they could and bind them to objects? Effectively eliminating the chance of them causing mischief? What would happen if say they had a repository of these objects bound full of Daedric souls and the Daedra then became unbound through aome manner?

I am envisioning a Temple devoutee quoting scripture and the Sermons as they bind these Daedra away or banish them. Might use it as a roleplay idea. Could be an interesting but more laid back plot device too. A Vigilant of Stendaar might work as well. All the hate they aik at the Daedra backfiring as they bind countless Daedric souls to items to remove them from the possibilty of causing trouble on Nirn.

Hmm. I would write a longer post, but I am short on time. You are incorrect, they do have bearing in lore

Here, check these out:

http://www.uesp.net/wiki/Daggerfall:The_Obsessed_Child

If I remember correctly, Daedra have a 'potonymic' (spelling).
A secret name that when spoken banishes them back to their realm.
Each secret name can only be used once because it changes after it is used.

I vaguely remember reading this in a book somewhere but Ill be darned if I remember which one.