Good points, some of them, but very very far from practical in a realistic scenario. The cat is out of the bag, and how would you imprison people who pass around mere 1s and 0s?
Just like you imprison somebody for carrying carbon, hydrogen nitrogen, and oxygen.
It's the same stuff that your body is made of, how can somebody go to prison for that?
Nobody will go to prison for 1 and 0 but you will go for prison if what those 1s and 0s make together is something deemed illegal just how you're going to prison for C21H23NO5.
If a government would want that much to get bitcoin eliminated from the economy they will not target the chain or nodes or the hash rate, they will go after users.
As I said before and others did, if they would make holding cryptocurrencies a felony with mandatory 25 years, would you still use it?
No 51% or Sybil or any kind of attacks orchestrated by the government will happen.