OK after reading this whole thing let me start by saying that I'm Brazilian...and like I said above, I was 15 and went to Disney in July as my 15th birthday present.
It's a common gift...either girls want to have a 15th birthday party (similar to a Sweet 16) or they get a Disney trip. Boys usually choose Disney or another trip.
Culturally, Brazilians are a lot more in your face and touchy than Americans. A person's bubble doesn't exist, it's in your face for real.
When I went, I never experienced leaders telling us to cut lines, we were actually told not to but it doesn't surprise me.
Brazilians are direct, we speak our minds which is a good thing and a bad thing.
At Disney, a lot of these kids are away from home for the first time and the leaders take them to the main attractions at first and then the leaders go chill out and these kids are loose in the park...that's when it bad things happen.
You also experience horrible shopping experiences and that's because the leaders are paid a commission over the total sale their group generates. The questions I heard at check out were, cash or credit? Who's your tour guide?
As for the singing, I'm not sure about American cheer groups but Brazilian groups are asked by the leaders and by the filming crew (each trip comes with a video of the trip) to sing and show oneness as a group...it's totally instigated at first and then it becomes the norm as the trip goes on.
I'm proud of being Brazilian but even when I travel to Brazil, thanks to my barely noticeable accent, I pretend I'm not Brazilian and speak English to the attendants because I'm treated a lot better.
It's sad...
In Summary: I would avoid Disney in July...because that's exactly what happens...kids are let loose at the hotels, leaders don't control them very well and there's not much they can do...parents pay a ton of money to make this happen and the travel companies just let it happen.
I tell my wife, our next trips will be late May or early June, around Thanksgiving, or the Holidays that while there are still a lot of Brazilians, it's mainly families as the teen groups only show up in January or February after the holidays since Brazilians as very much family oriented.
Now on to the vocabulary lesson:
Cala a boca - Shut Up
Com licença - Excuse me
Não fure a fila - Don't cut in line
Sáia da minha frente - Move out of my way
Respeito por favor - Respect please
Quietos por favor - Quiet please