I totaly understand the problem with spam comments. But if somebody has the right answer, He/she is right.
Maybe if you limit the amount of guesses. Like 10 per day for names and 10 for questions. It will be more structured. They can choose between these 10 questions, highest will win. And if the name is correct, but it will take time, then it is one out of 10 but still the right.
Other questions and guesses will be ignored/deleted? So nobody has to read tons of comments.

I hope I could help, the idea is good 😊
Good luck