I'm currently running 2 games, one party with Keto & one without, & ran into a couple of bugs in the "Keto-less" party that correspond to where her interjections happen in the "Keto-ful" party.
The first one was with Edwin's tasks for Mae'Var - when he sends you after Reyic, Keto makes an interjection, but since she wasn't in my Keto-less party, the quest broke & stopped there (I had to use SK to advance the variables to move on).
The second time was during the first meeting with the Avatar of Amaunator in the temple under the sewers. Keto has an interjection while you're discussing Amaunator's followers & the rod, but in my Keto-less party, the dialogue just stopped & the Avatar had nothing to say to me (I SK'd in the 1st half of the rod & proceeded from there).
I doubt I'd have guessed that Keto was the cause if I hadn't been running 2 parties, & it may just be my configuration (I have a ton of MOD's installed, so if I'm the only one this happens to then it's obviously something I did), but I figured I'd point it out in case anyone else can confirm that having Keto installed but not in the party can break certain quests.
Incidently - shouldn't she get drunk if you use her Bottle of Wine over & over?
- Imrahil