Agree with pretty much everything listed so far :)
I'd add the 'all cheerleaders are skinny/petite/tiny' stereotype. Ok, maybe if you're cheering on a college co-ed squad and you're female, but there are so many AMAZING cheerleaders out there who are tall and make great back spots, or strong and make great bases, or who are amazing power tumblers with intense muscles, or great dancers with strong dancer thighs! Thankfully I haven't encountered it much, but I have been asked how I can be a cheerleader if I'm tall and not particularly slim. Um, easily! If I tried to make myself skinny, I'd have no energy for cheer, as it's just not my body's ideal type ;) I love seeing the different body types and shapes at competitions, with all of the young women (and men!) proving how wonderful body diversity is :)