The question ought not to be, should Canada take over Quebec's taxes or should Quebec take over Canada's taxes? The question ought to be, how do we simplify taxes for Quebec residents? I certainly think there is a way. I mentioned automatic tax filing. That would help a large percentage of individuals not to have to deal with a complex, two-form system.
There are ways to manage this without overhauling and investing huge amounts of money and taking the risk that the end result doesn't work as well as the product we have today. That's all I wanted to throw in there.