Some Questions About School in England

So I have a few questions about these things. Of course, I could just do some research on the Internet, but I figured I might give this a shot. It's for a story I'm thinking about writing.

The Questions:
School

1. In the U.S. the elementary school is grades K-5, middle school is grades 6-8, and high school is grades 9-12. In the U.K., do other words replace "elementary", "middle", and "high", and do different school have different grade levels, like how in Japan, middle school goes to 9th grade, not 8th?

2. What are the basic school subjects? Do they have any technical terms?

3. What kind of grading system is used? For instance, the U.S. has A-C, then F (D was abolished, for some reason.). A is 90-100, B is 89-80, C is 79-70, F is all other scores. Is it different in England?

4. How does the graduation go? Is it pretty much as shown in the movies, or is there a difference?

5. Are there more uniforms/dress codes in English (public and private) schools?

If these questions seem silly, I'm sorry about that, but I really would like to be informed about these things if I'm writing about them.

Also, any big differences in speech between the UK and US would be helpful to know.
Like when we have a test, we say "test", but I hear "exam" in movies. Those kinds of differences are the ones I am referring to.