Dangerous was a filly, as May Carleton said when she told Tommy about the horse's name, the fastest she's ever ridden, but Tommy refers to the horse as 'he' in his eulogy.
At the 36th minute Tommy watches through a stained glass at the street. It is not possible to watch through a stained glass, and there is no sign of a broken piece.
Polly refers to Ada's future baby as being "the color of a Hollywood Oscar". The Academy Award statuette wasn't commonly called an "Oscar" until 1934 while this is set in 1929.