i add the paypal api info and now this info is shown if

i add the paypal api info

and now this info is shown if i want to test the price buttons

Pypal is set "live"

There was a problem connecting to PayPal to setup your purchase. Please try again.
10401 – Transaction refused because of an invalid argument. See additional error messages for details. – Order total is invalid.
10431 – Transaction refused because of an invalid argument. See additional error messages for details. – Item amount is invalid.

with the setting "sandbox" this error is shown

There was a problem connecting to PayPal to setup your purchase. Please try again.
10002 – Security error – Security header is not valid

and what about the api login facebook, twitter. do i have to use them to?