That was a fun little quest, and I have a couple of thoughts how it can be made even better.
During the walkthrough I had a following problem: when Neel Gymont asked me to bring him 5 bowl, obvious choise for me was to get those from the local potter - Voatrix Xania.
Unfortunately for some reason she don't have a Barter option in the dialogue, so the only way to acquire any pottery from her is to steal it, which does not make any sense.
It would be nice to have more legal option.

On the UESPWiki I've found that you have an option to inform the guards that Neel Gymont is trying to find a skooma dealer
That however was not the thought I had, while doing the quest. I wanted to inform the quest giver - Emilia Vicci of the same fact, to see her reaction. But sadly, she does not have corresponding dialogue option.

I think those two options are relatively easy to add, but would sufficiently improve the quest.