Note that while .Net tools will auto-generate web-service calling code from the WSDL, some people argue that doing that is short-sighted http://martinfowler.com/bliki/TolerantReader.html.
However, I assume you are dealing with people who want to do that anyway.
If it is only a few specific web service functions you want to call, then one option is to just had-write the WSDL for calling those methods (including the details that Moodle currently leaves out). I did that once before MDL-20804 was fixed. I think that the reason MDL-28988& MDL-28989 have not been fixed yet is that they are quite hard, but it may just be that we have not yet had enough eyes on them to make them shallow. Moodle's SOAP implementation is based on Zend, and I don't know when we last imported the most up-to-date version of those Zend libraries.