I use a lens hood and a hand strap.
(This one: http://www.bhphotovideo.com/c/product/744403-REG/Canon_4991B001_Hand_Strap_E2_for.html)
I was hesitant before getting the hand strap that it would interfere with vertical shots, but it's not a problem at all. I just take my hand off the strap, flip the camera, and shoot away.
I've never had my camera damaged as a result of somebody bumping or running into me. The other person has walked away rubbing whatever unfortunate body part contacted my camera, though. I use the Canon 1 series, and they're built like bricks. Add a flower petal lens hood, and you really don't want to run into it.
Don't fixate on the 1 series, though. I've tripped and fallen on a 5D before (was strapped to my hand, and it broke my fall), and it suffered no ill effects. :)
Cameras are much tougher than you'd think. I wouldn't intentionally set out to determine exactly how tough.
I would not put filters on for low light scenes that include bright lights. You're more likely to run into unwanted reflections.