I am very happy that we have the Community as a resource to discuss issues openly where we can even vent our frustrations. We all have days where things just don't seem to work.
I was not aware there was a new customer phone support. In my case it was the VAR that got things done when PTC didn't.
There are many times I have been very upset with the tech support personel. There is anescalation process you might want to look at if you are in dire straights for a quick reply.
I don't know what to say about your STL export. In general, it has to be a solid volume (I also found that enclosed facet models work). I guess you already worked with the options in the export? Have you tried to set them courser rather than more precise?