If they ever go this route, I imagine they'd offer a deposit insurance. Either way, if they offer this as a service, they should be liable for any losses. There's really no point otherwise.
Aren't banks suppose to cover the losses of their users and peers should a hack or loss within their vaults occur? Anyway though, it seems that more and more institutions are getting their hands on blockchain and crypto tech. Most banks relied on obscure security practices back then, and I think it's about time that they do something innovative on the way they handle other people's money.
In part, yes. Most giant companies and institutions will just incorporate a part of a cryptocurrency and get a patent about it, make some innovations and voila!