Nop.Core.NopException: Failed request (BadRequest): Request is not well-formed, syntactically incorrect, or violates schema.
Well, I see two different errors in these log records:
1. Your "Merchant ID" does not conform to the expected format. Usually it looks like "2UP72RCCHVA4L" (letters and numbers), but in your case it's too long and numbers only. Perhaps you should contact PayPal support.
2. Postal code shouldn't contain spaces. All settings in the admin area are trimming (spaces at the end of the line are removed) when saving, but in your case there is a space in the middle of the code, so you should edit it yourself.