Although I'm unsure about all the ramifications, this idea has merit. Thanks for proposing it. You touch on some important psychological issues, like expectation that are unmet, and the disillusionment and disenfranchisement from not being able to get rewarded or make an impact early on. It's a different system/model.

The influence/power issue is the main reason why steemit userbase is not growing and retention stats are poor, you can do all the marketing you want if you keep the system as it is this community is going to stay in a corner of the internet and die a slow death as demand for steem keeps shrinking.

The way the power of voting is distributed is definitely an issue that has long been recognized. I believe the plan was for people to slowly move up over time through gaining SP, but that may not be feasible if other expectations (like keeping users) demand something else to be done instead.

I'm still not sure how viable this is at this point, but I agree on most of the benefits you stated. I'll have to think about it more I guess. One thing is how after you get to a certain point you can't support other's work anymore through your own upvotes.