the 10002 error means that paypal is not accepting the API credentials. This can happen for a couple reasons:
- You are using Live Credentials in sandbox mode or vice versa
- You have not accepted the billing agreement
- sometimes the credentials are just bad, you may need to generate new ones.
For the shipping issue, if you don't restart the browser between testing it may be that the shipping response is from the old pages.
make sure to close the browser completely between tests.
also If you re run the checkout wizard, make sure to delete the existing checkout pages first.