By "you can airthrow someone in hitstun", do you mean even normal air throws? Or do you mean specials like, what you said, Heat Knuckle?
EDIT:
I have ANOTHER question, lol:
If my attack is still in the startup frame, and someone poked me out of it, is it considered as a CH? And, are there any circumstances where I poke out an attack and someone poke me out of it will NOT result in CH?
And, my previous question which was "How come red background appear when Ky (In GGXX/) 5D'ed me while I am in the air?" not answered so I thought I would post it here again...
Thanks people!
EDIT:
ANOTHER Question:
I was wondering if you could mash out of Slayer's ground throw before he kicks you... Since there is a wag-your-joystick motion to the first part of his ground throw. Has anyone done it before or is it impossible to do?