Are these sentence grammatically correct?

Are they grammatically correct?
As a non-native speaker studying English Syntax, I need native's linguistic intuition about following sentences. Do you think they are acceptable?


(VP Preposing)
They say he may have been killing flies, ...
1. ...and killing flies he may have been. [ ]
2. ...and been killing flies he may have. [ ]
3. ...and have been killing flies he may. [ ]

(Negative Vp Preposing)
They say he may not have been killing flies, ...
4. ...and not have been killing flies, he may. [ ]
5. ...and been killing flies, he may not have. [ ]
6. ...and killing flies, he may not have been. [ ]
7. ...and have been killing flies he may not. [ ]
8. ...and not been killing flies, he may not. [ ]
9. ...and not killing flies, he may have been. [ ]

(Though movement)
10. Killing flies though he may have been, still he is afraid of killing flies. [ ]
11. Been killing flies though he may have, still he is afraid of killing flies. [ ]
12. Have been killing flies though he may, still he is afraid of killing flies. [ ]

(Coordination)
13. He may have been killing flies and have been killing ants. [ ]
14. He may have been killing flies and been killing ants. [ ]
15. He may have been killing flies and killing ants. [ ]

(RNR)
16. He may, but she may not have been killing flies. [ ]
17. He may have, but she may not have been killing files. [ ]
18. He may have been, but she may not have been killing flies. [ ]

(Pseudocleft)
19. What he may do is killing flies. [ ]
20. What he may do is been killing flies. [ ]
21. What he may do is have been killing flies. [ ]

(Insertion)
22. However, he may have been killing flies. [ ]
23. He, however, may have been killing flies. [ ]
24. He may, however, have been killing flies. [ ]
25. He may have, however, been killing flies. [ ]
26. He may have been, however, killing flies. [ ]
27. He may have been killing, however, flies. [ ]
28. He may have been killing flies, however. [ ]

(Response)
What may he have been doing?
29. Killing flies. [ ]
30. Been killing flies. [ ]
31. Have been killing flies. [ ]

(VP deletion)
May he have been killing flies?
32. He may. [ ]
33. He may have. [ ]
34. He may have been. [ ]

(Do so)
35. He may have been killing flies and she may have been doing so.[ ]
36. He may have been killing flies and she may have done so.[ ]
37. He may have been killing flies and she may do so.[ ]