I agree the two problems you presented can be tough to solve and are interesting problems to consider:
1. Managing egos can become a problem, maybe some sort of ability for users to tag comments with logical fallacies to try and encourage rational arguments?
2. Could users use some sort of anonymous verification for throwaway comments? A global key to sign their anonymous comment? There's definitely work done in this category, I found https://link.springer.com/chapter/10.1007/978-3-642-36213-2_... after a quick google.
I think you bring up a slightly different point in the end, the gatekeeper/moderator is a much harder problem to solve and related to the clash of egos. Ultimately, rewarding critical thinking, limiting power of censorship and growing the community organically are key here