2. Right, but not only for the reason cited, since drawing a 4 and a 7 together would also satisfy both events.
3 & 4. I believe you also have the right answers here. See wikipedia [http://en.wikipedia.org/wiki/Complement_(set_theory)] for an introduction to this notation (The c should be in superscript, though.)
5. It seems like you don't actually need help with any of this. Gook work.
If there is any part of the wording other than the bizarre complement notation that confuses you, point out what it is so people can try to help.