White Christmas/Headscratchers

They sit the general behind a giant cake, completely blocking his view of the show. And why is there a cake with candles anyway? It's not his birthday.
- It's the tenth anniversary of that night from the opening of the film.
Suddenly the farmhouse has room for a gigantic purple set with enormous stairs and a full auditorium? And then they hide the purple stage and enormous set pieces somewhere and replace it with ANOTHER differently colored set, and show them rehearsing elaborate song and dance routines with vaudeville jokes with a huge chorus line of girls... and all of that gets cut at literally the last minute and replaced with one military song and a closing christmas song? Featuring NONE of the dancers and sets and stuff? It pretty much made all the random scenes of them rehearsing into big lipped alligator moments.
- Um, there was a timeskip between "I Wish I Was Back in the Army" and "White Christmas." Didn't you notice the montage? Besides, even with a sudden heavy snowfall it takes more than ten minutes to get that much snow.
  - That still doesn't explain how the stage and room they were performing in is ridiculously smaller than the area they were seen rehearsing those dance numbers. There's no physical way they could have jammed all those dance numbers and props and purple floor to ceiling set into that one area.
  - Actually, it's not -- there are enough wide-angle shots that establish the size of the bare stage and show it's no smaller in those shots than it is in the production numbers. What makes it look smaller is what appears to be a removable proscenium arch which narrows down the performing area when it's in place.
And lets not forget how the ENTIRE dilemma with Betty would have been avoided if she simply stated WHY she was upset. By the way, how was she able to find a glamorous job in new york in less than a day?
- She had the job. Remember the busybody telling her about it after using steam to open the envelope? Sure, the club was expecting two Haynes Sisters and not just one, but the job was waiting. And remember that Betty was the practical one; she must've been sending letters looking for a post-Christmas job the entire time.
Why isn't there any resentment among the cast of Wallace and Davis' stage show when they completely restructure the long-running and successful show to turn two young and attractive blonde unknowns -- with whom they have obvious romantic chemistry -- into co-leads?
Emma's eavesdropping is responsible for Betty's departure, so why is it that when she's brought into the conspiracy to keep the General away from the TV (which clearly involves telling her what's really going on), Emma doesn't tell anyone -- or call Betty herself -- to clear up the misunderstanding?
Betty clearly couldn't have rehearsed or been fitted for a costume for the military-themed numbers in the special show for General Waverly -- if she had, she would have known the truth about the plan. So how was it that she fit in seamlessly to the performance, right down to choreography that would have had to have been very different for three people?
Why does one of the soldiers assembling for the reunion have a thick German accent?