The following link nicely expains general public restroom decorum. I'm certain further items can be added to the list. For a full description, refer to the site:
http://www.tipdiva.com/2008/06/06/top-ten-tips-public-restroom-etiquette...
- Do what you need to do and leave
- Be respectful of others' number twos
- Keep your eyes on the wall or yourself
- If you happen to splatter on the seat, be sure to clean up after your self; this is especially true if it's a stall.
- Flush... Dammit
- Warn others of lacking toilet paper
- Don't speak unless spoken to (perhaps this is more true in the female restroom; in the male restroom, no talking. period.)
- Don't answer your cell phone while you are on the toilet (more on this in a future blog)
- Throw your garbage away
- Wash your hands... seriously.
Of course, many more rules and addendums can be added to this truly non-exhaustive list. It is interesting that this came from a predominately female blogging site.
Does anybody disagree with any of these items on the list? What others can be added?

Number 3 = very important.
Does anyone ever follow the 4th rule you listed? I don't think I have ever seen anyone cleaning up after themselves. I can't say I have ever. That would just take to much time and make other guys wonder what I am doing. I don't even sit on the seat in the first place, so I could careless.
Flushing is a big problem, but again I don't do it. It takes an extra step I just don't want to perform (say what you will...... I am lazy. I know this). It also has to do with a germ thing. If I don't touch it... then I don't have to worry about germs. Problem Solved.
Others seem straight forward and I agree with.