Hi, Quiggin. Good points. No, it's not the most ethnically sensitive number. Times were different then, as you observe. I like the number, and for some reason I find it easier to accept than Fred Astaire's Bojangles turn in blackface in "Swing Time" - and that routine is a superb piece dancing and cinema choreography, one of Astaire's best. Go figure.
However, I do think “Pass That Piece Pipe” is highly defensible as cinema choreography as well. Charles Walters may not be Vincente Minnelli, but he could be awfully good, and I think he handles the very big groups in “Peace Pipe” and “Varsity Drag” in masterly fashion. Notice, for example, there are relatively few cuts in two very large and quite long numbers. That takes a lot of skill from director, choreographer (Robert Alton worked with Walters) camera operators, and performers, and plenty of sustained energy from the latter, as well.
(I do not like McCracken's makeup - too much - characteristic of MGM in that period.)
I agree that Allyson's singing voice is pleasingly different from her speaking voice. I like very much her rendering of "The Best Things in Life Are Free" in Good News.
Off topic - perhaps I’m oblivious, but I don’t see anything particularly offensive to Native Americans in the phrase “holding down the fort,” which I have heard regularly, usually around offices on short-staffed days. Yes, early America had forts and some Native Americans did attack them, but forts have gotten attacked in many places in many eras, no?