Credit card and credit score: fact or fiction?

[misshark122]

2 questions I have:

1. Does opening a new credit card lower your credit score? specifically I am thinking of opening a bloomingdales card.

and

2. I've heard it is better for your credit score to keep open unused cards with no balance on them, than it is to close out the card? Is this true?

I think I have 5 credit cards... a J crew, a Banana Republic, a Capital One, a USAA, and an AmEx. None ever carry a balance month to month. I never use the USAA and I never use the Banana Republic. Will closing them affect my score negatively? Right now my credit score is very high.
Thanks!