Thug: "Rough up" Threaten someone (and maybe deal a small amount of damage) to intimidate them/get information/money.
Witch: "Curse" Roll a dice and note its value. Can subtract this number from the target's roll within the next 24 hours.
Poisoner: "Poison handshake" The poisoner touches someone with a slow-acting poison on their hand. (The Poisoner is immune to their own poison.) Around an hour later the target gets stomach cramps or diarrhoea, maybe takes small amount of damage, etc.
(I'm sorry but I don't know how your game system works, hope these are appropriate.)