Frank,
I am using the latest version of Xivap, not XSB, and I wouldn't like to dispense with any of the plugins I am currently using; they are there for a purpose and I will be glad to explain why I think they are so useful but this is hardly the place.
I may have found why there was an incomplete metar file, which did not cover the particular airport I was departing from; this may have been caused by my temporarily disabling NOAA, which may have caused the metar to be incomplete. However, if you say this wouldn't cause an RWC crash I have to accept your word. I hope I can stop using NOAA once x-plane 10.50 becomes final, since it will provide wind and turbulence aloft globally; incidentally, the code for that has been partially authored by Joan, the designer of NOAA plugin.
José