"It is certainly possible to imagine a system which decouples curation and tipping/reward and it's probably a good idea to do so because it would have a number of positive knock on effects."

This. The present curation mechanism also has a number of negative effect that severing curation from rewards eliminates.

"Specifically as regards downvotes, the idea of "free downvotes" as it stands already violates one of the central axioms of the system, effectively that your stake determines your ability to affect the distribution of the rewards pool. Giving people free 100% downvotes means that your stake is effectively multiplied when it comes to reducing the power of other people to be rewarded from the pool."

This too. I expected a far different result from EIP, and remain mystified why we got what we did. I'm glad we got this result instead of what I expected, but I do not understand why we did at all.