Could you please check these sentences?

Hello! Could you please tell me whether it is grammatically correct to say these sentences even though they may be strange ?

1) Their acts strike me as criminal.
2) Those people strike me as criminals.
3) I think of these discussions as academic.
4) I think of these discussions as intellectual.
5) I think of these people as intellectuals.
6) We think of their ideas as lunatic.
7) Their ideas strike me as lunatic!
8) We think of some people as lunatics.
9) Some people strike me as lunatics.
10) His works strike me as visionary./ I think of his works as visionary.
11) Those leaders don't strike me as visionary (or visionaries)
12) I do not think of those leaders as visionary (or visionaries).
13) French people are alien to this country. (or French people are aliens in this country).
14) They saw us as alien to that country (or They saw us as aliens in that country).
15) They think of us as alien to that country (or They think of as aliens in that country).
16) These ideas strike me as alien.
17) These creatures have green hair and ten fingers. This marks them as aliens. (or These creatures have green hair and ten fingers. This marks them as alien ).