I have only just discovered Plan-G and have yet to use it, but I have to say that the manual is probably the best I have seen in FS.
Obviously manuals for programs like this are written by people with a deep and long-standing understanding of the program, but all too often the writer presumes that we are equally gifted and understand what they mean.     Either that or they jump all over the place or skip over important details. 
I am an FS8 user but even so I was very impressed by the detail with which you describe the apparently tortuous interaction with FSX.
The Plan-G manual is clear, detailed and (so far) easy to follow - and thats coming from a guy who hates manuals, pays little attention, and gets very stroppy very quickly when he doesnt get his way.

I hope that my experience with the program itself will be as positive, and in a way, it would be nice if I never have to come back to this forum again.
Well done.