Thanks for your feedback! With the potion master, keep in mind that individual potions when rolled randomly on the Shadowdark Item Attributes tables can be extremely strong, especially for first level.
Also, if the Potion Master is able to enhance potions so that they are effective on skin contact, the idea is that they can start throwing potions with curses at monsters using a Flask Sling. And because each of these Curses, once distilled, is a "simple" that can be turned into new potions, as the Potion Master collects powerful curses, they will beable to rain down on enemies cursed potions (each special sling flask would contain one potion, this might not have been clear.) At the beginning, in the early levels, it is likely that Potion Master is more of a support class, but at later levels with tons of curses they can become extremely powerful (hopefully not too much).