Banks can't work with bitcoin, search "fractional reserve". Banks may offer some Bitcoin services in future but it won't replace fiat services nor it will be possible to seamlessly juggle/ exchange between bitcoin and fiat.
What are you talking about, it would essentially be a shapeshift style thing where you enter the amount of use it buys that much off an exchange and sends it to the address you entered. Totally possible.
I'm talking about loans, credit cards etc., it wouldn't be profitable for banks to offer bitcoin loans, look at payday loans - banks would have to make their fees that high in case of bitcoin loans because they wouldn't be able to just write off unpaid loan just like they do (to some extent) with fiat loans.