I agree with what you say about its strong points, but the george also had some big disadvasntages, or caveats that we need to take into account in the wash up....in summary i see the George's problems as
1) The george spent a lot of time grounded, mostly because the homare engine that powered it was unreliable. Ki 100 engine was proven and much more reliable. Consequently its serviceability was better.
I dont know about the airframe. George (I) had problems, George (II) was a redesign to address this, but I am not sure the redesign was completely successfull. Will concede, however that the main problem (the undercarriage) was fixed in the Model 2
2) Lack of altitude. George could not fight effectively at B-29 altitude. The Ki-100 still had difficulty, but could do it better than the george (sorry about the non-technical appraisal).
3) Performance. Georges were attached mainly to elite units, eg the 343 AG. This is likley to prejudice the outcomes of air combats against it. As far as I know (but not sure), Ki 100 units were not over-populated with Aces in the same way as the george was
4) Both types suffered from low speed, a common problem for late war Jap planes. Mustangs and Thunderbolts were 70-80 mph faster at altitude, which is where it mattered in '45