There is no word 'recentness'. You could say ' Please confirm that the documents are current and correct'. The word 'valid' usually covers these conditions: ' Please confirm the validity of the documents'.

Technically, yes. However, it's awkward. What exactly is the context? You could just say "Make sure the documents are correct and recent" or "Make sure they're the most recent documents." "Correct" in this case is a little awkward in general. If you want to say "the intended/appropriate document" it would be better just to say "the right document". Again, I could probably give a better sentence with some context.