Everything above sounds good to me except for the 50/50 split in Author Rewards and Curation Rewards. I do agree that there should be more curation going on but then again if the Author Rewards are decreased this drastically then there might not be as much content to Curate.
After all a huge part of people here on Steemit wants to get some sort of earning out of this and if it gets reduced by 25% that would be a huge blunder, especially when there is a rumour of EOS launching their own Social Network.
I for one believe the 75/25 split I'm favor of Author Rewards is a perfectly balanced ratio. Plus now if we get the 15% Down vote pool we can somewhat counteract the One Liner/Picture Posts that has no context at all.
RE: My take on HF21