Awesome post.
It seems to me that Bitcoin is sooner or later going to be put into its "core competence" territory which is, more or less, conducting shady deals around the globe, gambling, and acting as a gateway to the more exotic, not directly tradable cryptocurrencies.
However with the emergence of functional cryptos (Steem being a great example of that - a blockchain tech that actually does something tangible outside payments), its cut of the marketcap will probably decline and then stabilise, reflecting its true scale and functionality.