hello everybody,
do “could not have…/would not have …” form questions? If so, how?
A) Could he not have seen me?
B) Could he have not seen me?
It is also possible that these structures are complete nonsense and or sound unnatural but I can not tell since I am not a native spreaker.
Thanx
Those structures make perfect sense. 
So are they grammatically OK? Word order too?
Yes
Also possible with a different meaning:
‘How could he not have seen me?’/ How could he have not seen me? (How is it possible that he did not notice me? - which indicates that the speaker was in clear sight.)
thank you, much appreciated.