Since
Raynor already provided the correct information which was asked for, I can only add my own opinion on the whole thing. Streaming from my imaginations, as you said,
MatthewM, Faramir and Denethor 100% beardless, as well as Imrahil. They were all described as really "true-Númenorean-heritage-bearers"; and Faramir always seemed to me also quite young to have some really distinctive beard (lesser than Boromir at least); while Denethor was more of the high politician, I liked him in the film, almost as I imagined him (well, except the tomatoes; but no beard). On the other hand, thinking about it, I always imagined Imrahil with moustache... (although I think especially about him it is explicitely written that he was completely beardless)
Anyway: Aragorn and Boromir. I must say that now, after twisting my imagination with the movie characters popping up here and there, I have no problem in imagining Aragorn or Boromir bearded, somehow I even adopted Boromir-with-beard picture (but mainly because I have one picture of him bearded, by John Howe). But before the movies came out, I never could possibly have imagined Aragorn or Boromir with beards! It never came to my mind: and it was just natural, before I have read anything about beardless Númenoreans. Maybe Tolkien would have written about it if A&B were bearded?
I don't remember much how I felt when I first saw captions from the movie, but I think it was the short spot in TV where the pass of Caradhras was shown with both Aragorn and Boromir, and one word comes to my mind: BLASPHEMY!!!
