Logic fail. Presidential elections are FPTP - can't be any other way cause there can only be one president. UKIP was largely an electoral failure because of FPTP (only getting 1 seat with 12.5% of the vote). Where UKIP did well in the European Parliament and council elections which use PR. IOW, you are making my argument for me.
A fallacy with no basis in reality. The FPTP system forces Liberals to consider what happens in the next election so they can't afford to alienate marginal voters so the do represent the voters that did not vote for them. Under PR, we get these fringe parties that don't care about governing the country. They on care about imposing their policies on the majority and PR gives those parties the power. PR is the true tyranny of the minority because of the incentives the system creates.
First, Donald Trump does point out major flaws in the FPTP whether or not you want to accept it. It refutes your assertion that it can keep extreme right-wing elements out of politics.
Second, Republicans gerrymandering has led to the current system where a vote in the Midwest essentially counts as 1.25 votes in urban areas so face it, FPTP system has its own flaws.
Third, if why bother even having a multi-party system if we are essentially a two-party system?
Fourth, you are trying to equate the Greens with extremism, but they're not. They have major backing making them NOT a fringe party. Reality check, just because TimG doesn't agree with something, does not make it 'extreme'.
Fifth, you are conflating federal system of government which controls immigration with provincial politics. Though you're free to make it a point in a federal argument against PR, it has no place on this thread.
Sixth, even if a federal system, Canada is not Europe. Even our European ancestry is mixed and we are not a homogenous society. We are less nationalistic and less likely to fall into the fallacy argument you're making.
Seventh, minimum threshold. Enough said.
Last but not least, even if your boogeyman argument comes true and we get to the point that extreme-right makes up a huge portion of Canada, what do you have against a true democracy where politicians represent the will of their constituents?
You are being very paternalistic in that you think you know everything and everyone else is just too stupid to know what's best for them.