Throughout the economy of Quebec today, I think it should be better for Quebec's own development if it has been separated from Canada. Then Quebec can develops itself instead of under the control of Canadian's Federal Government which makes Quebec's original people live poor till now.
Consider this: leaving Canada would put greater pressure on Quebec to support itself. It would need its own resources, abilities to import and export, and industry enough to provide jobs for those who live there. If it is not able to do this already, what makes you think it would survive on its own independent of Canada?
Hard for me to comment eloquently on whether another culture and people should declare independence. There is certainly some tension between my British Columbian and Albertan friends and their Quebecois countrymen to the east, but from a practical viewpoint, I have a hard time seeing Quebec as a viable country to itself economically. Certainly the rest of Canada isn't sustainable as a nation without the economy that Quebec contributes, and the converse of that is probably true as well. While it has been a while since a vote has taken place, the people of Quebec don't seem to have majority support among themselves for separation either.
I doubt that separating from Canada would be easy, and it would likely cause more harm than good. For example, consider the US Civil War. It is not realistic to assume that if Quebec wanted to separate from Canada it would be allowed to without a fight. Chances are, a lengthy civil war would result or the issue would be dead in the water at the get-go, damaging relations between Quebec and the rest of Canada for a long time after.
There are some similarities between this situation and other countries with parts that want to become independent, such as Scotland or Wales in the United Kingdom. Unfortunately, the reality is, as #2 makes clear, that it is rare for these sections of the country to be able to make it on their own as they are, to varying extents, subsidised by the country as a whole. In addition, in a sense, Canadians living in Quebec are already recognised for their diversity in terms of their langauge and culture. So what would they gain?
I'm not sure that leaving Canada would help.
First of all, Quebec does not really produce more than its share of Canada's GDP. Its GDP is about 20% of Canada's and its population is 22%. So it's not as if Quebec is contributing more than its share.
Second, according to this link
Quebec gets more money from the federal government than it contributes in taxes. This means that the rest of Canada (specifically Ontario, Alberta, and BC) are subsidizing Quebec to some extent.
Quebec's GDP per capita is somewhat lower than that of Canada as a whole. But it is not clear to me that being part of Canada is actually a cause of this disparity.