Not to jump out in front of Adair, because you're in good hands with him, but a few thoughts:
1. The tree is weak, not enough to cause concern. Some good sun, a heavy feeding regimen, and the daily attention one can provide when it's in a personal collection vs. a larger nursery, and you'll be surprised what it can do over the next year.
2. It appears to have been candle-pruned this summer, but the disparity in buds produced at the various sites shown indicates unbalanced energy. This is corrected by fall bud selection, and needle-pulling. Adair is good with discussing this.
3. Based on how you describe the soil, I'd be hesitant to repot unless it's organic & mushy, or simply not taking water. I think we tend to pot too often. Once you get the roots "right", pines like this should be on a 10-year repotting schedule.
4. Nice trunk line, fantastic bark. The branches highlight it nicely, and with time, it will be vigorous and balanced enough to make a really dynamic bonsai with it.