When players play more minutes, then they have more time to get injured.
So I think that 1. is yes
Sure, but I don't think that 2 games of 24 mins each give you a higher chance than 1 game of 48 minutes, which I believe was the question.
"I don't know half of you half as well as I should like; and I like less than half of you half as well as you deserve."