Paul:
You are getting lots of good pointers from some real experts. One thing you might try is to loosen the hall sensor plate a retard it a few degrees. Lots of times they are set for maximum RPM and advanced so far that it makes starting harder. Worth a try and is easy to do. Be sure and mark the housing where it was first located so you can return it to the exact location if need be.
Paul Eagon
PS Did you get the tailwheel yet?