Hi BSB,
>1). The major production version of this fighter was the KI-44 IIb which I have seen to be armed in 3 ways, 4 12.7mm mg, 2 12.7mm mg 2 20mm Ho-5 cannons or 4 20mm Ho-5 cannons. Do you know which one is correct?
I haven't personally done any reasearch in that matter, but I remember a discussion somewhere where a lot of guys went looking for photographs to prove the use of 20 mm cannon in the Ki-44, and if I recall correctly, they ended up empty-handed. The only cannon for which photographic evidence could be found was the 40 mm recoilless gun.
>2) I understand that the KI-44 shoki also had a excellent roll rate do you know what it was?
Unfortunately, I don't have any data on roll rates :-(
>3) You state that the Shoki's top speed is slow but I have seen it listed as 376 mph is that really slow compared to other AH aircraft below 10,000 ft?
Well, below 10000 ft it was at its best, and it wouldn't lag much behind most contemporary planes, but it is a mid-war fighter, and if you pit it against late-war fighters it's inevitably to look slow in comparison.
It undeniably has a bit of a sweet spot at low altitude, though, a bit like the Fw 190A.
Regards,
Henning (HoHun)