Etiquette rules

As you may imagine, there are many things that are culturally different here than in the US. Here are my top 3:
1) No lines. Nobody here lines up for anything. It is a free for all everytime you need to get in line. Sometimes, there is a line but if you leave just the slightest space between you and the next person, someone will suddenly wiggle in front of you. Personal space rules don't apply. Most of the time, it is just a chaotic group of people huddled together in front of a counter trying to get served next (i.e. today I had to return something and was cut in front of 3 times before I elbowed my own self to the front and shoved the receipt in the clerk's face). I guess in a country of nearly 2 billion, you just have to shove your way in or you'll never get served.
2) Spitting. As in hocking luggers everywhere and anytime. The more phlegm the better. And I mean on the sidewalks too. More than once I have been walking down the street and heard the tell tale sound of someone about to spit when suddenly from a bicyclist riding past me a huge ball of mucus comes flying towards me and narrowly misses my leg.
3) Public urination. Apparently OK around here. As I was out for a walk this morning, a taxi driver pulled up just ahead of me, leaped out of the car, and proceeded to take a whiz on the sidewalk right in front of me.
It is for reasons #2 & #3 above that all people in China take their shoes off when entering some one's home.