Thanks for the shout-out @organduo. My concern about 50% curation rewards is that it will not be sufficient to change behaviour. 75% curation should work because frontrunning will be more profitable than delegating to bots. This will reduce the number and size of bots as accounts will switch to frontrunning or delegate to other more profitable causes.
I wrote a five part series discussing problems and solutions. Here is the link to the final post.
Is the Steem ecosystem in disequilibrium? (Part 5 – Combination of solutions)