Here's a few suggestions following a common theme of weapon/update stats, history, and trivia.
I'm only suggesting T/F and multiple choice questions as it would be difficult to use a bot for open ended questions, so I'm limiting possible answers.
Suggestions:
Answer by typing [T/F] in chat (True or False)
The enforcer when it was first released dealt a bonus 25% damage at any given time. (False)
After the 'Jungle Inferno' update was released, heavies could abuse sandviches to have millions of health at once. (True)
The 'Jungle Inferno' update was the first ever 'Pyro update'. (False)
The Demoman's 'Loch-n-Load' does 25% less damage to players. (False)
The Scout's 'Soda Popper' requires a 'Crit-a-Cola' to craft despite having a 'Bonk! Atomic Punch' attached to it. (False)
Answer by typing [A/B/C/D] in chat (Multiple choice)
The blue moon update was released on what date?
A. February 16, 2018
B. March 13, 2018.
C. January 29, 2018
D. March 28, 2018 (Correct)
What class has the least amount of unique (non-reskin) weapons?
A. Demoman
B. Engineer
C. Medic (Correct)
D. Spy
The Scout's 'Baby Face's Blaster' with full charge will grant him what movement speed?
A. 150%
B. 200%
C. 75%
D. 175% (Correct)