So the only development is that he digs out the nut and bridge a bit to lower the action, and files down the frets so that they don't buzz?

One problem with lower frets is that if they get too low, it takes *more* finger pressure to fret a string (frets are worn on my old guitar, and certain notes are tricky). I think these changes may not actually give you much improvement in playability, particularly if you're using medium or heavy strings. And the setup to the nut and bridge, I don't see why anyone half-awake and halfway competent ag guitar couldn't do it themselves with a file.

Graham.