The most obvious error is in the title. It should be: Are these sentences correct?
2 is the only one that's a little odd, but only in a couple of minor ways. 'Act' isn't a very positive word. Perhaps 'art' would be better? In the second part of the sentence, you seem to be saying that they are...enjoying...the possibility. I'm not sure people enjoy possibilities. Perhaps it should be 'appreciate the possibility'?
The rest are fine.