For me, the question of volatility is not addressed sufficiently. It is of crucial importance if Bitcoin wants to be successful as a currency and not only as a speculative asset ("digital gold" is only another word for that).
It isn't easy to address that in a decentralized way via "infrastructure". But an intelligent design of incentives is definitively possible, for example providing tools that let people profit from stabilizing the price (e.g. with easy to use "contrarian" trading bots) and new services by payment providers like a
"backing" option for merchants.
I was going through your thread and it was indeed an interesting idea. But what I feel is that where Bitcoin itself is struggling to maintain its position in financial landscape, would there be enough merchants for backing Bitcoin at a scale that can impact price at all? I believe this idea won't work without the interference of some centralised institution and also, unless there is a diversity of services and products that act as backing agent for Bitcoin, it will struggle to make any difference as people won't be buying anything just because they can get it cheaper during crash. At a point where Bitcoin itself is not mainstream, this idea will not work out. We atleast need a decade of growth of cryptos to even think about it.