While I agree on many of what you mention above, at the same time I feel it's all wrong. Those who will receive the downvotes are more likely to "retaliate"...so chaos indeed. It'll definitely become personal. I don't really think the a separate pool for downvotes is what we lack of...
As for the good content that needs to be discovered....it can still be found...do we really need a 50/50 reward system to wake up the whales and be more active?
How's that gonna help a newcomer? or a guy with 500SP whose vote at the moment is almost none existent? How will they be benefited from that? Hoping that they will receive a vote from a big account that wouldn't have landed on their post in a 75/25 reward system?
Everything is already complicated and it's gonna get worse...that's my point of view...
I'm sure those doing the downvoting will be aware of this, if not there's always going to be a lot more upvoting power to help undo what others may find was unfair downvoting due to retaliation. There could even be guilds spawning to do just that.
How much stake is locked up in bid bots/other right now? 50 million SP? 80? It's not news that everyone will go for what is most profitable to them, in this day and age it is also pushing those that would want to curate to do the same thing cause else they're left with lower stake in the end than those going for max ROI and not caring about curation and rewarding authors.