RE:NASDAQ and US dollars question. Unrelated to unlisting - in terms of minimizing exchange fees look up Norbert's Gambit.
A Norbert's Gambit takes 3-5 days to exchange your currency, but it'll be for a fraction of the fees. It's definitely worthwhiile if you are dealing with large amounts of money going between USD/CAD on exchanges.
When I first started investing I didn't realize that exchanges were shaving 1-2% every time you converted. Noerbert's Gambit is common - if you buy a fund like DLR.TO - and you call into your broker, they know what you want to do.