1. No. Just move your eyes around the circle. For example the majors for the Key of A is D and E.
2. Yes, it gives me a basis to start with.
3. Progressions are not my strong point. Someone else?
4. I took music lessons and it was explained to me. I have not read any books on the topic but probably should.
5. Yes, there are rules and rules can be broken.

Hope this helps...

...Deb