Multiple classes of coins is in my view definitely scary. I'd love to be as optimistic, but I cannot in good conscience. If a government can devalue your coins and/or make them less useable by their decrees, you are at their mercy. That is exactly what btc is supposed to prevent.

That's the problem of creeping centralization. Right now, we can see giant server farms and data stores. There is a definite, relatively small number of them, that can be coerced if needed. I expect something similar to happen to miners too. I don't think any government would purchase their own hw and secretly do a 51% attack. The vector of attack here is regulation of already operating miners.