There was a time when messages didn't have scores. ;)
I like the idea of the score modifying placement in the comment tree, but not being visible. I also like the idea of a more expressive score (maybe normalized), I suppose like the emoji systems do, to indicate funny, angry, etc, rather than some silly binary.
I think most of the answers to your questions can be answered by the question that this comment section is responding to, to understand the framing that I'm commenting in:
But, this is the first and last Reddit related thread that I plan on participating in, so I'll be cheering with you, if we ever get the miracle of reddit evaporating. Although, I would be worried where they would all end up.