If everyone is using their 2.5 full downvotes a day ( I suspect it will be more like 1-1.5 on average), that puts more in the pool and more in the hands of those 10x votes that are incentivized to find content that won't be downvoted so that they can maximize their 50% curation. If it does work this way, it means that the maximizing behavior of curators benefits who?

It maximizes the benefits for those who actively go out and seek things to downvote.

In that single statement is why the rest of your post doesn't matter. It's a fantasy. It's a fantasy build on observations about human behavior which no one believes because they are simply not true. I won't say that this is a lie because I believe that you believe. But it's wrong. Elementally.

The core problem is not a technical issue but instead an utter misunderstanding of how and why people use social media platforms. They do not go to a social media platform in order to find or be exposed to content that they don't want. They go to a social media platform in order to find, consume, and enjoy the content that they believe should be rewarded. At worst, they get exposed to content that they're not interested in.

Following, upcoming Communities, the underlying idea of "curation," it's all about communicating to the system your preferences and expecting to get more back. When people receive content they're not interested in and in fact think is overrated they don't immediately think "oh, I need to downvote this," they think "this social network is a piece of crap; it's giving me stuff I don't want." They don't see it as their responsibility to do things for other people at their own expense.

We been told over and over again that people don't downvote because it's too expensive in terms of voting power – and in part that's true, but they don't downvote for much more important reason:

They see content which requires down voting as an elemental failure of the underlying platform.

And that's because it's true.

So, let's ask the question from the other side of the coin. Who is it that will have the most use for downvotes?

People who go out of their way to seek content for down voting. People who have been involved in the Whale Wars before and have consistently used downvote vote power to abuse and harass others. People who take it on themselves to go and police others. Bot owners who realize that downloading content which is associated with their bots effectively provides a bit more of the reward pool for themselves.

The mechanic rewards most the people who are most likely to abuse it.

That's why it's a bad design and why ultimately it will lead to less creator reward and less creator activity on the platform. Best case, it leads to another Whale Wars spike but the participants are too busy going hammer and tongs at each other to notice any of the rest of us. Worst case, the creative space on the STEEM blockchain is made to that much more vulnerable to someone at random coming along and bumping some of your already scant reward for reasons absolutely unrelated to your content.

It's very difficult to get excited as a creator or as an analyst about any of this mechanism. I wish more people were talking about how questionable it is from a position of process.