I think you missed the point I was trying to make about crypto-currency.
You don't buy a hamburger with your MSFT shares. You don't buy a BMW w/ gold. You spend cash on all of that. This idea is what I hold for cryptocurrency, whether people see it this way or not is a different story.
Currency is a faith system that we all need to believe in for it to work, otherwise it's useless.
It's pretty obvious everyone sees it differently, just like how people saw the ARPANET differently. Ideas and perspectives changes over time, and the same will occur for blockchain.
Regarding the IRS, yes, I pay my gains taxes like most everyone else. I'm not expecting any leniency now or in the indefinite future, which is why I do my research into these things and cover my ass.
But will they ever request all previous Bitcoin addresses? I think it's interesting to ask these types of questions, but you should come up with follow up questions too. For example on enforcement. Kind of like with the drug war, it's hard to enforce unrealistic policies.
You should Look into what it means to be anonymous vs private. Depending on how you do it, your addresses can be anonymous, meaning pinning your identity to any Blockchain address is... Hard. Which is why enforcing anything with crypto is hard. Transactions can potentially occur between two anonymous parties.
This is when you get into Blockchain forensics...