Thanks for writing this up; a platform is only as strong as its foundation, and in this case, Steemit's foundation is its users unless the devs have their own private idea of how the platform is built. There's already a high learning curve when it comes to even signing up; once you get over that, then there's high turnover as users spend a lot of effort on posts without recognition.
(I've turned to comments, myself, haha...)
The other thing is that power is concentrated in the few; the few have a very limited attention span because of reality and math. So even if the platform grows tenfold; all of them could be creating quality content but only a few can be rewarded due to the nature of the economic system.
So I like your ideas as a way to start; although I admit 50% curation for say bidbots makes me a little leery. But in general something does need to change for the long term prospects of Steem; I guess if I were to throw out an idea, maybe a 'sponsored community' where whales are mods but delegate power to help communities grow - I think this kind of already exists but something more developed might be nice without having to jump on discord to join random groups...
Power is not concentrated in a few. This is capitalism. You can work yourself to the top. Welcome to the free world!