Questions regarding credit card APR

p.s. It's not about maxing-out as many cards as possible. As I stated above, part of your credit risk is based upon the ratio of Credit Used / Credit Available. So having many spare accounts increase the denominator, which means a lower credit risk, which means a higher Credit Score.

A higher Credit Score gets you a better APR on a home mortgage, a car loan, and surprisingly Homeowners Insurance. Right-or-wrong, Insurance companies maintain the opinion that if you have crappy credit, you are more likely to submit a claim against your homeowners insurance. So higher credit score = Lower Insurance Premiums