Gateway returns error "The transaction failed because of invalid input data."
Your HSBC merchant account is currently in test mode but it is marked as Live in your store. You should call HSBC Secure E-Payment Service and ask them to put your account in Live mode. It will solve the problem.
"The data for element 'GGG888888GG' ClientId is not valid. (file: CcxXmlInstance.cpp, line: 793)"
Client ID must be a number, not a string. You also cannot use its Alias.
"Insufficient permissions to perform requested operation. (file: CcxInput.cpp, line: 902)"
You are probably trying to use a test account in live mode or vice versa. Also make sure that you are using correct username, password and Client ID.