Huh. If Cinia is here on Tel Fyr, it means that Morrowind Patch Project is installed in some form, as she did not exist otherwise (and there was no ability to train Medium Armor to Master level without her). Interesting observation, but not really relevant in the current situation.
We do need to make sure to gauge Divath Fyr's reaction to minor revelations before letting him know more world breaking information; preferably after requesting his assistance. We don't want to end up as experiment material to a 4000 year old possibly insane Telvanni wizard. Though the fact he runs the Corpusarium shows at least some amount of hospitality.
Aside from mentioned above, inquire about his ability to travel between realms at will, and if it can be learned or performed upon others within reasonable safe limits. I recently read in my own Morrowind playthrough the Varieties of Daedra book, which mentions this ability as something he and he alone possesses. Additionally, if he seems okay with answering the above question, ask if he has knowledge of the realm of your origin, showing him the cell phone, some of the non-ruined paper of your note pad, and possibly the t-shirt as focus points for where you were originally from.