Oh don’t look it up, the pictures are gnarly

Yes. Yes they do.

Not necessarily. It’s a very physically demanding practice and a lot of the forces are borne by your feet, but with good practices plenty of dancers avoid injury or pathology.

Pointe work is especially demanding and is what people usually think of as causing damage, the bleeding toes etc. But it’s entirely possible to work en pointe healthily. Also, pointe is less of a universal demand in ballet than it was a few decades ago, and there are plenty of professional dancers who never work en pointe.

Usually injuries are the result of overwork and incorrect habits, just like they are in every sport. There are certainly teachers and schools out there who push people past safe points and cause damage, and harmful attitudes that you need to “push through the pain”, but again that’s common to every sport.

They have a series of huge health issues caused by ballet. It’s a horrible, toxic culture leading to eating disorders and a lot of miserable people.