I have full confidence in Biden. Sure, he isn't his 2012 self, but Trump has always sucked at debates. It will also finally put Trump in the spotlight of having to commit to issues and probably garner some ad/campaign material. And Biden may finally get an audience he needs to sell his accomplishments and draw a contrast to Trump. This race needs to be shaken up somehow even as debates likely won't matter by November.
I think even the timing can benefit Biden, this could possibly happen after Trump gets his verdict in the New York case and around the time the Supreme Court will release some surely controversial rulings.
This would help Biden.
The landmine will be Israel, trought.
In a way, yes. Although it finally forces Trump to take a position on the matter.