That's a great interpretation, Scarlett. I think as a producer or director it would be great fun (on someone else's money) to put a new Show Boat together from all the available pieces in the tool kit. Wikipedia has a great and long summary of all the changes and revisions and additions and subtractions from all the major stage productions and films.
The first act is much stronger than the second. Almost all the standards are introduced in the first act. "Bill" and "Why Do I Love You" are second act. (I hated giving that song away to Elaine Stritch, but I figured it was her price for accepting the role.) Kern's original finale, "It's Getting Hotter in the North" has never been used in the major Broadway productions or in any of the films, although it's a fine song. CATSNY says it was in the recent concert production.
The second act is up for grabs. You have to have Gaylord leave Magnolia, Magnolia sing "After the Ball" on New Year's Eve with her father in the audience, and Julie years later running into Gaylord and showing him the newspaper clip. After that it's pretty much carte blanche.
I think some have missed the different versions of the Gaylord Magnolia reunion. In the original stage production (and in the Prince) when Gaylord encounters Magnolia Kim is a Broadway star. Twenty years have passed and pretty clearly Gaylord and Magnolia are not going to pick up where they left off.
In the MGM film, by which most know the show, only five years have passed, Kim is a child and Ravenol and Magnolia are free to reunite.
The first act is much more structured, but there is leeway there as well. The dirge "Mis'ry's Comin' Round" was cut from the original production I thing because producer Flo Ziegfeld thought that it was just too downbeat. Still, Kern's original overture remained centered around that song. Hal Prince not only included the song but made the miscegenation the strongest element of the plot. (Prince also restored the original Overture, bless him.)
There are many more songs written for new productions and films than can fit in the show. So choices must be made. All the songs written for any stage or film production are collected in John McGlinn's three CD set which features Frederica von Stade and Teresa Strata.
I don't think sensitivities have changed much in the 25 years since the Prince revival played for almost 1000 performances. Show Boat was anything but a racist show. We know Hammerstein. He brought out the hardships of the life of the blacks and the racist laws that worked against their race. Show Boat was also the first show to have white and black performers on the stage at the same time.
"Ol' Man River," if the song and its message are taken together, for several decades was recognized as the best song to emerge from Broadway. When I first saw Ol' Blue Eyes, then a skinny young white boy, sing it in the Kern biopic, I thought that it absolute heresy,. But in his maturity he sang the song quite movingly. His two daughters say that when Sinatra sang it in a benefit concert in Carnegie Hall, Martin Luther King wiped tears from his eyes.