It looks good. I have a ror pitch pine that I started a couple of years ago. Next spring will be time to repot and see how it is coming along. I'm looking forward to following your progress.
My only comment would be that this not the ideal time to work on roots. Pitch pine are tough so you might be okay. I would try to keep it frost free over the winter.
You are correct, this is better done in spring buuuttt:
A. This is a very tough species (as you had said).
B. Roots were teased out with a small wooden stick, not removed.
C. Spring is busy, so I wanted to do it now during a lul in activity.
D. I keep my trees in a shed with a space heater, so deep freezes are not an issue.
E. The previous soil was reused and spread around the roots, so the bacteria could continue supporting the tree.