Actually it fits the Steem blockchain perfectly.
Some thoughts:
- all data can be on chain
- voters vote on answers directly so the authors can get author rewards
- for good questions, the ones who asked them can also get author rewards
- voters would get curation rewards, vote relatively early to get more %
- A reward from the author is also awesome
- appropriately use tags so the questions can appear on the trending page of steemit.com
- Use
json_metadatato do deeper classification (credit: @good-karma) so you can play with them on your site