A) NI is in a bit of a pickle - if and when Brexit eventually happens, they've either got a visible border, or they're out of the UK, or the Backstop's been implemented. Options 1 and 2 would both more than likely lead to a resurgence of the Troubles. There's more animo for nationalism amongst the neutral these days, though, who were strongly in favor of unionism 20-30 years ago. As for numbers, I'd say the 40% is closer than the 90%
B) Today was an interesting day. In response to Boris' attempt to
completely ignore the public will make democracy more lean and efficient by sending parliament home for 5 weeks, parliament has voted that a no-deal Brexit cannot go through. WWhen Boris next pushed for a general election, Parliament refused him that, too. Good luck, Boris! I honestly don't know why the EU would want to keep the UK in anymore, though. They've cost us enough in economic downturn and slowdown and dragging all other decision making in EUrope to a standstill. God only knows what happens if Europe says "Backstop or no deal", now, though.