‘Doors! Why doesn't this place have any doors?’ 
Nice poke at the inns of Skyrim!
What a ‘gonna punch her in the mouth’ scene this was! I don’t know whether to be more pissed at Alva or Onmund. Unless he truly is under some mighty powerful magical spell, he’s in big trouble and Kayla needs to consider the utility of a future with him. Since he seems somewhat of a mage himself, I’m not optimistic - one would think a mage would be able to detect the employment of such magicks against him and take steps to counter them. Argh!
And Kayla storms out of the inn right into a compelling quest. Hmm. . . seems Alva’s a common thread somehow.
Now, let me confess at this point that I'm an Oblivion player and don’t play Skyrim. Please bear that in mind when I share my perceptions with you as I may not know the boundaries between your fanfic and Skyrim quests/events. It’s actually kind of fun reading this way.
I learned here that Kayla has some history with the Dark Brotherhood – and apparently it didn’t go well for them. Also, unless I missed it earlier, I see Kayla knows some of that ‘word shouty magick’ where you cast special spells by yelling at folks.
Your extra editing efforts paid handsomely with this episode. Here’s the only tiny nit I could find:
‘Completely blind with with fury, I didn't put on warmer clothes or any armor before leaving the inn.’ (an extra ‘with’)