Do my customers need a PayPal account to pay me through PayPal?
Whilst PayPal do strongly encourage users to either login to an existing PayPal account, or create a new one, your customers do not need to do so in order to make payment to you.
Your customers just need to click the 'Pay by Debit or Credit Card' option on the PayPal payment page.
Please note however that if your customer attempts to pay with a card that is registered to a PayPal account they may have to login to their account in order to complete payment.