No if you look all the oxford cloths are done with a box pleat and no darts, they cut them with the same features regardless of the sizing (slim or regular) they're trying to preserve what makes an ocbd an ocbd. The proper "dress shirts" ie. spread collars etc. all have darts in slim fit.
I can't believe this is serious, but most of my Jewish friends have boss suits and they're fine, lot of em drive Benz's too. As long as you don't walk around with an SS armband or a swastika tattooed on your forehead I think you'll be fine.
Cafe wise, Myriade right next to Guy metro is always great (on Mackay), or this place called Piccolo on Park near Mcgill, or as said before jst walk around Mile End the plateau (Toi Moi et Cafe is a staple).