Private
That all sounds quite remarkable. Although I expect that at those speeds Quidditch is a little more hazardous than it used to be!
Yes, well, some things are their own fault. If they didn't bring their own brooms to school, first-years shouldn't be surprised if they're given whatever spares were left behind by others. I was flying competently long before I started school, of course, and on decent broomsticks. We had to learn broom repair in Slytherin just because the captain thought it important.
The appropriate manner. Yes. Small improvements, not startling innovations in a century where they don't rightly belong.