I must admit I am not sure whether what I went thru is termed Validation or Conversion.
I did, however, complete the steps you first identified in this thread.
I also got a Licence with the term "based on a PPL issued by the United States" - or words to that effect - printed on it.
The assumption that my UK licence was only valid as long as my FAA licence was still valid (BFR etc) is mine. However, this is what I was told by a number of other people at the time. I may well be wrong.
Either way if you are going for the route you describe I still stand by the advice to do all the written papers and avoid any complications.
Cheers