OP,
Blockchain is a cryptocurrency specific technology, one might have thoughts about using better data structures for this purpose but the opposite side is absurd: There is no other serious application for blockchain.
There is no "technology" named blockchain. it is just an inefficient messy data structure used in bitcoin, nothing more.
Yes but you can use the blockchain, wether the bitcoin blockchain or another one as a pretty powerful record keeping and transactional machine. Cryptocurrency act as the financial security that ensures this record remains secure (nobody wants to lose money) it is two sides of the same coin. no, the only application of blockchain is not just currency transactions. but also secure information.