I don't think the voting system is particularly relevant, here. The erosion of civil rights will continue for as long as Canadians put up with their elected members of parliament representing their parties, first, instead of their constituents. Preferential ballot is great, to an extent, but there are also several other alternatives that I think would make the situation worse, to the point that I question whether it's worth opening that can of worms. As I see it, the problem is mostly cultural, anyway.
With the current system, every Canadian has a particular MP who depends on him to be elected again, and that MP can theoretically side with his constituents over his party without destroying his career. If MPs depend on their parties to elect them, for example, we lose that and we're basically picking an emperor (albeit in a way closer aligned with the popular vote) along with the number of lackeys he has.
The thing we really need is parties to stop treating their MPs like liabilities. On that note, there is a promising discussion going on about MPs' freedom to speak: http://openparliament.ca/search/?q=standing+order+31
With the current system, every Canadian has a particular MP who depends on him to be elected again, and that MP can theoretically side with his constituents over his party without destroying his career. If MPs depend on their parties to elect them, for example, we lose that and we're basically picking an emperor (albeit in a way closer aligned with the popular vote) along with the number of lackeys he has.
The thing we really need is parties to stop treating their MPs like liabilities. On that note, there is a promising discussion going on about MPs' freedom to speak: http://openparliament.ca/search/?q=standing+order+31