Your UPS account information seems incorrect. I tried using it to log in at:
https://www.ups.com/lasso/login
and that didn't work, so I think it is wrong.
I fixed the USPS shipping so checkout does work now.
It appears your paypal credentials are incorrect as well. You should be getting those from the API access section at paypal here:
https://www.paypal.com/businessprofile/mytools/apiaccess/firstparty/signature