I noticed a few anomalies while playing, so I had a closer look at the items with NI.
Oak Club +1
Uses 'None' as its proficiency and has 'Quarterstaff' listed as the proficiency in the description
Poisonkiss Staff +1
Uses Quarterstaff proficiency but the description says club.
Poison, Virulent Poison
Has 'Missile Weapon' listed as its proficiency in the description, though this is a BG term and not BG2. The items themselves have 'None' set in the item file for proficiency. Having to use them as weapons is a bit counterintuitive--all other potions are targeted out of the quickslot (such as Firebreath or Acidic Explosive). The other problem is that they're not flagged as potions so they can't be stored in potion cases. It seems that the rationale is that it can only be used on one person, ergo we want a to-hit roll. If that's the case, I'd rather have these potions work like an assassin's poison ability where I can coat my own weapon and do poison damage that way.
Staves
The staves all have "Not Usable By" in the description, though they're usable by all. Monks can not use staves.
Non-healing potions
Wizard slayers are not allowed to use magic potions outside of healing ones.
Sleeping Powder
Uses a bag icon when in inventory, but when moved around it changes to a scroll. I'm not sure if it's intended or not but it is set as a scroll item meaning it can be stored in scroll cases rather than potion cases.
Acidic Explosive, Concentrated Acidic Explosive
Former uses a fireball animation and does not stick around for 10 rounds as promised. Neither of them do acid damage.
The Rock Golem has nothing to say to me; even a generic "the golem stares vacantly" line like the ones in CI would be an improvement. I strongly suggest the herbs be spread around the game as the current system is suboptimal.