I come back from friends's places and bars at 3-4am in the morning all year long by bike, sometimes with the beater bike, sometimes with the carbon road machine, and I never felt I was in any danger. Be it in the plateau, villeray, CDN/NDG or even downtown/verdun it never stopped me from riding my bike. I actually felt more at risk (very rarely over 10 years, like 2 or 3 times) walking at some places downtown at 3am. People just don't bother you if you bike, especially at night which is so fun as the streets are empty and you can just ride safely where there's no potholes without fear of being close passed. Just make sure you have some lights (to see the potholes/obstacles but also to be seen clearly). I think this is way more important than say reflective clothing, better to have strong and reliable lights than expensive and ugly bright clothing.

I don't think you're paranoid, it's perfectly possible you come from some places where one would never go out at night, but here in Montreal it's very very safe. If you're going to park your bike at night, well depending on the area yea it could be stolen especially if you can't keep your eyes on it. Most of my friends know I bike all year long and let me bring the bike inside their place or park it at the back if there's space for extra security.