Of course it would need to be implemented after SMTs were up and running and giving Devs and business owners a bit of time to add value.
Yes, it would need some time, but keep in mind this post is merely to start a productive conversation. Because, as you said yourself, a vision is important.
However, why would we need to change curation rewards and add a flag pool if we went this route?
Those would be added into SMTs, where each SMT could decide how high author/curation-rewards should be and if a downvote-pool should be included. (so the downvote-pool would have to be coded anyway) E.g. Steemit Inc could decide to use their own SMT for Steemit.com.
Why would serious business owners and devs come and build on a blockchain that can't even decide what it is, what we do and how to approach it.
Because every serious business owner and dev should know that things change over time. New features are being introduced and old/deprecated ones removed. And Steem has clearly changed quite a lot over time - at least once SMTs are there.
Also, everybody can launch their own project, but steering it through tough times, that's where the real value is shown and where trust is built.