Your on the right track! I also use Thompson Ball Screws. Without getting into too much detail, just use a trial and error to get to the final results. Without being able to measure the heat on the surface, I can't tell you how hot I make mine. I heat "the crap" out of them, then turn. As for warping and distorting the screw, I have not had any problems yet. As with any process, take your time, use common sense and good machining process and you will do just fine.