Bit of a plothole though...
They are scared of the Walesong in the night, but end up maquerading themselves as British Wahling ship "Syren" later in the movie. Obviously they were familiar with traditions and details of whale hunting, so it seems hard to believe no one in the crew ever heard one before, or at least had heard tales of the singing.
Yes, these (with the possible exception of the weighing anchor scene) should have been left in.
as to the whales, well, if the crew had mostly severed in the Mediterranean, Channel, and North Atlantic, it is possible for many of them to not have seen much of whales.
As to being familiar with whales, remember (1) their masquerade did not have to be all that detailed to fool the French from a distance (mostly just not look or act like a man of war), and (2) they by that point had the whaler's crew aboard to help with some of the details.
That said, question like as you asked might be one of the reasons that scene was cut.
Of course, I have always thought the only significant plot whole in the movie is that
Acheron does not recognize
Surprise sooner, seeing as how she had already fought her twice, and, even with the disguise, the ship is the wrong proportions for a whaler (the
HMS Rose replica that plays
Surprise and the real captured corvette upon which the ship is based were longer and, at a greater than 4-1 length to width ration, noticeably sleeker, than the normal whaling ships would have been), something that should have become apparent even before
Surprise opened her ports and ran up her colors.