Cycling is a safe activity. It's gotten a lot more dangerous due to lack of respect on the roads / culture war bullshit, but in absolute terms, cycling is still an extremely safe activity.

I would say, it depends on you mostly. How you’re riding, how much you follow traffic rules and pay attention. And I think, that you can ride almost anywhere and it would be fine, if you know what you’re doing and are confident enough. If you look at those crazy messengers on fixies, riding in NY on youtube. They’ve learned to be very aware of surroundings and they can predict what’s going to happen 3 steps ahead and they don’t even follow traffic rules at all, they seem fine. But of course accidents can happen to enyone.

Yeah, it depends on your locale. Never the less, one should always be as visible as possible. I always wear a neon green cycling jacket with red led/reflective ankle straps.

In your situation I would also get led lights for my bike. Two red ones for the back, and two white ones for the front so you look as much like a motor vehicle as possible; also, (perhaps most importantly) a mirror or two so you can see behind you.

Basically you would want to look like a motorbike.