johnnyace 

1) Only by a dog. Chased me on a country road. Frame pump to dog snout took care of that.

2) I had to break a guy's nose once, back in '93, who attacked me with a knife, but I was walking, not on a bike.

3) I personally wouldn't change my habits because of some scumbag. The world can be a dangerous place, no matter where you are. But then, I've been in and out of martial arts since I was 5.