These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
It's quite well known in Salzburg because, well, Money, Dear Boy. Sound of Music Tours are quite popular.
Alternative Character Interpretation: Is Georg left heart-broken and harsh after the death of his first wife, only to be awoken by the beautiful music of his children, or was it because he realised how good a good nanny is for them after firing so many? Or does he warm up as he begins to fall in love with Maria?
Rolfe - oblivious and naive enough to be seduced by the Nazi regime or two-faced bastard?
More likely to be oblivious and naive - consider the average German covilian's reaction to the existence of Auschwitz etc after WW" had finished. This is detailed on doccos such as The World At War etc.
Big Lipped Alligator Moment: In the movie, "The Lonely Goatherd" was demoted to a one-off puppet show scene after "My Favourite Things" became the song of choice for the thunderstorm scene.*
"My Favorite Things" was originally sung by Maria and the Mother Abbess before she left the abbey (the first time).
Designated Villain: The Baroness. In the musical, the only thing she did wrong was be rich, unliked by the children, and choosing not to cause any trouble with Germany to save their heads. She was made a little cattier in the movie, but really at worst she was just preventing Maria from moving in on her fiance.
Ear Worm: Several songs from the movie have made their way into pop culture, including "My Favourite Things", "Do-Re-Mi" and "Edelweiss".
Ensemble Darkhorse: The nuns, of course! They dismantled a car to save an Austrian family from the Nazis!
If you know anything about Nazi Germany and what happens to Austria after the Anschluss, you sort of have to feel sorry for the Baroness, who is demonised for trying not to get into trouble with Germany, and Rolfe, who will likely die a soldier in the war (especially if you subscribe to the idea that he was naive enough to be brainwashed into the Nazi Party, not realising his actions would lead to the deaths of Leisl and her family). Honestly, every character villainous or otherwise (but presumed villainous for complying with the Nazis rather than escaping Von Trapp-style) is likely to face hardship or outright death in the coming war.