I like the points you make here very much, especially with respect to reputation. I think the tribe construct may help here, if we follow the examples of steemleo, creativecoin and stem where the focus of the group is maintained by moderating the content (as well as the tools will let them). If the proper discipline can be maintained in such tribes, then they become an asset rather than a distraction as I see many of the others to be. Improving the tools to support those goals would be a step in the right direction. If someone doesn't like the control a given tribe chooses to enforce, then they can go elsewhere. Then we need to 'market' those tribes to 'outsiders' that would be interested in them.
A shortfall I see with Steem in general is the difficulty (at least for me, perhaps because I haven't stumbled on how to do this) in finding material of interest that may now be deeply buried in the blockchain because of time and a multitude of posts. This would make the platform some much more meaningful (as well as useful for research), especially for groups like stem, tunes, and creativecoin. The information is there, just not easily discovered, filtered, and presented.
I would also like an effective way to filter out specific tags (I found a setting for it, but it doesn't seem to work, at least on iOS where I spend most of my time on steem-y stuff). I really don't care about peoples activefitness and such.
To me, the nature of the blockchain as an enduring repository almost demands that its contents should be of a more timeless nature or a snapshot of us as a people/culture/society at a given point in time. (though I must admit that I may have departed from that goal on occasion).
Finally, bitcoin has been successful as you pointed out in the beginning because it does one thing well - it provides a medium of value exchange securely, inexpensively, and (relatively) quickly. These are things commerce values. Steem can do that as well, but again the tools are not as well suited for that (like integrating into a third party shopping cart). But then again, few of the non-bitcoin systems have done well at this, either.
Steem can be many things to many people, but not all things to all people (at least not yet :). We as a community need to decide what things we want to be for what people, figure out where our shortfalls are to do that and start focusing on resolving those. Along with that, we need to figure out how to differentiate ourselves from other like projects and articulate that to the world. This is starting to happen, but if the roadmap for that was posted a while ago, I haven't figured out how to find it yet ;)