We use PayPal as our payment processor, so we accept Visa, MasterCard, American Express, and Discover. Or, you can pay using your PayPal balance.
Yes. You pay through PayPal, the world's premier electronic payment solution, not through this site. We never even see your credit card number; PayPal just tells us that you've paid and we ship you your stuff. We get your money through PayPal later.
No, you can pay with your credit card without a PayPal account.