For currency, The Maldives, with a relatively small population and tiny GDP has their own currency. What is the difficulty in currency? Ignoring the fact that AB would probably just use the greenback.
All of these of these issues are surmountable.
Does not mean "easy". It means they can be overcome.
If they opted to go with the USD, they'd have to trade all their CAD - which will undoubtedly take a huge hit if they separated.
I still think that separatists would say that Alberta doesn't have to deal with a share of the debt and that would be a sticking point.