Okay, I'm going to attempt to sum up your position. Correct me if I'm wrong.
Basically, you're willing to bet that the alleged upside (i.e. EU breaks up) is worth the potential downside (i.e. fascism, discrimination, alienation/purging of minorities, closed borders, economic ruin) of having right wing, white nationalist parties rise to power across Europe.
So, ignoring the merits of your anti-EU position, which I know is something ME has dealt with in depth... I think you're being blind and naive to the potential harms that will come from the rise of white nationalist movements. We've already gotten a glimpse in the U.S. after two weeks of trump. We've already seen a documented rise in violence against minorities/racially inspired violence/hate speech in the UK, Canada, and the US. Even if all your assertions are correct about the benefits of breaking up the EU (which we'll just have to agree to disagree on), you're dramatically underselling the danger of the risks.
In no way could I argue that your desired ends will justify the means. You basically see racists and white nationalists as a necessary tool to break up Europe, ignoring any harms and costs as collateral damage for the greater good? You realize these are borderline white supremacists? And you want to put them in power all across the continent in the hopes that it will sow further division?
I think you're being dramatic.
These right wing nationalists movements aren't nationalist socialists. There isn't a Hitler among them. None of them have thugs at their Beck and call hunting down people. They all seem to respect the Democratic process and European countries have strong checks and balances to guard against authoritian regimes, arguably better than in the USA.
The geopolitical situation on the ground isn't the same as the 1930s. Same as in the USA, and perhaps brexit, there is going to be a bit of pushback from these insurgent parties, but do I see state organized violence against minorities? No. Will certain extremist groups and individuals participate in Quebec City style attacks? Definitely, but I cannot directly lay blame at the parties, for while they may inspire these things, they aren't out ordering muslims and immigrants to be killed. Same way I don't blame islam for radicals attacking people.
So no, I don't see a fascist Europe, I don't see a purging of minorities. I do see closed borders, a natural reaction when the borders have been wide open for decades, I don't see economic ruin, for I am pretty sure European nations can see the sense of free trade.
This is democracy at its core. When you have large organizations completely disconnected with the people on the ground you get these results. The EU has been stumbling and bumbling for close to ten years now and it's still to this day telling people everything is fine the way it is, no need to reform anything.
You have establishment parties telling people the status quo is fine even through a decade of low job growth, weak economic performance, and rising racial and social tensions. So I completely understand and sympathise with people who are frustrated with the status quo and mainstream parties that haven't done much to address it.
So to sum up, I don't see fascism, I don't see economic ruin, I don't see organised state sanctioned/tolerated violence and hate speech against minorities and immigrants. I don't see everyone who votes and supports them as racist. I do foresee a end to the EU, a period of adjustment followed by a return of mainstream parties at some point when people feel that they get the message.