Far from the biggest menace, but there is one nit I have to pick that somewhat aligns with the OP.

Pedestrians who don't look up to notice that the cars aren't stopped because the light is red, but because the light is green and they don't want to block the box.

As a cyclist in the bike lane/cutting between stopped cars, these people are dangerous. Especially when you try to get their attention since they're about to walk into your path, and they suddenly realize they're in the middle of an active intersection and freak out and quickly move in a completely random direction. By all means, keep up with your sudoku while crossing the street, just make sure the light is on your side before you wander into traffic.

I also once saw a guy walk straight through a construction site and nearly bonk his head on a giant concrete pipe hanging from a crane overhead.

And yes, I think a safer city would have no stoplights and everyone would have to be aware of their surroundings and negotiate moving through traffic, but while we have stoplights, you kind of have to play along.