I believe you made some great points in this article. I do agree that as it becomes difficult to expand the money supply for cyrptocurrencies they become more attractive vehicles for holding wealth and for diversification.
With regards to rate increases affecting the price of cryptocurrencies, I think when the Federal Reserve or other central banks raise interest rates it's having similar effect of cryptocurrencies as it would on any conventional currencies. As economists love to say is that people love to respond to incentives. Rate increases by the US Federal reserve as well as other central banks tend to make their currencies more attractive as short term and possibly long term interest rates rise for assets such bonds denominated in those currencies.