Did you modify the deployment descriptor file after your made copy of it. check whether you can access your servlet first. if no correct it then correct your deployment descriptor then you will get your html file.
Your server has User Define objects ( Your own class ). try to do one thing write a small server side method like addNumber(int a, int b). Which returns a + b; . Know try to test it with your bpel code.
Are you getting the web services input parameters dynamically, are you creating the input paramters and passing them. if you are getting then dynamically try to convert them to their respective types and pass.