So, I was thinking about the rules Stake and some users use on the giveaways and challenges. Like, to participate on some events, you need to have a minimum post count, don't have any bad rep/warnings/issues, along with other things. I think it would be really helpful if the author had access to some settings while creating the Topic.
Here's an example: Let's say I want to create a giveaway, and i'll only consider users who have a 35 minimum post count. Perhaps there could be a functionality to block people with less than the minimum post count to comment on the topic. That would lower the spam amount, prevent people trying to enter giveaways/challenges they are not yet elligible for, and would save the OP a lot of time. This functionality could be accessible at the moment of creation of the topic. I don't know if that's possible, but maybe it could be helpful.
Hope you consider it,
All the best!