probably not a good idea to destroy data in the age of information. i think it can be very useful (and in some cases even necessary) to have a possibility to trace transactions deep into the abyss. that's why the blockchain is also called the distributed ledger. imho, the security of cryptonite's mini-blockchain is doubtful. new coins are matured instantly and no confirmations of transactions can be made (it simplifies the task of an alternative chain creation). one of possible workarounds for us could be some blockchain compression or a light version of the wallet which uses the merkle root for transaction confirmations as in bitcoin's MultiBit.
I for one don't really care about destruction of data, it's probably even a bit of a good thing as it can add to the anonymity and decentralized nature of the Blockchain. Blockchain compression can only go so far, for something to really be infinitely self sustaining it should work like a rolling Blockchain where old data is pruned off otherwise you still have the growing ledger. I am pretty sure that a multi-bit like wallet using the merkle root only isn't able to Stake (or atleast not currently).
I agree, but the nature of crypto is not only in anonymity (there are also other ways to hide transaction history rather than just simply erase it), in the ideal world there will be no need in anonymity
The idea of the blockchain is something that can be saved in centuries hermetically sealed, it opens a road for extension of its functionality to let it go beyond money transfer. If it is the trade-off to save some disk space, I predict that in few years even 100 GB blockchain won't be a problem (Moore's law is still actual), with all it's synchro hashing work. So a compression or some harmless truncation (or full-blockchain master nodes, in the case of the multibit-like light wallet which can ask for a piece of the blockchain to be able to stake) can be a temporary solution to release back the full power of the blockchain later.
I'm divided on this, but mostly I fall to the side of keep the data forever.
I also suspect that storage won't be a huge issue going forward. HDD's just keep getting bigger, and SSD are getting bigger, cheaper, and more efficient as well. Plus, there are things like Electrum, though I think at present it couldn't work for staking coins. Somebody correct me if I'm wrong on that, because a thin client for Hyp would kick ass.