First of all, don't worry about the trolls. Trolls gunna troll.
Second of all, thank everyone for taking time to help me out. You are kind people.
I really needed this. I know what strength does in the game, I knew what intelligence does, charisma ended up confusing me.
Looking at all these view points, I think the one that sticks out the most is just let it play out. The third player is a sorceress with 15 charisma so it's not like I can set them up for for something that she could defuse.
All the topics brought up have made me realize what aspect charisma can have in the non combat world.