Comma, colon, etc...

Sometimes I find it difficult to choose the correct punctuation for some sentences like the following:

1. Could you tell me more about the following {,,}
a. project A; and
b. project B {/}

2. The sentence {,} Nobody should be liable {,nothing} {,} is misleading.

3. The preposition {,} of {,} should be used.

4. John F. Kennedy's quote {,nothing} "Don't ask what the Country can do for you, Ask what you can do for the country" was meant to be taken in spirit.

5. I am not going {,} but I am not coward {, } as I think you could handle it independently.

Thank for helping.