Refactoring a WADL - is it possible in Soap UI Pro version?

Yes, in fact I would call it 'good practice' to do it this way.

1) Import the WADL into SOAPUI in normal way.
2) Edit the Service Interface within SOAPUI, add/edit/remove Services, HTTP methods or parameters, etc.
3) Export new WADL file, generate documentation.
4) Even use tools like Wadl2Java etc.

See following link for more detail

http://www.soapui.org/REST-Testing/work ... vices.html