Well, I don't see the government using the blockchain beyond financial reasons, it will be too risky for them. Using it for marriage registry, licence and so on as you said (if at all possible) is tantamount to piling too many vital national information in a blockchain and I wonder what would happen if bad heads have an access to it one day. The top world government will prefer what they are used to.

Yes, I believe the government is now looking at the blockchain as the next way to go by for finances, but they are still considering the impact on the existing business which I so much agree with. For the second, the blockchain is also a thing of the app, I suppose you wanted to mention fiat apps, which I believe will fade away quickly if the blockchain technology is successful.