When things start going wrong in an aircraft for real unfortunately they don't come in the form of multiple choice questions. Better to understand the theory and get 90% than memorise the question bank and get 95%.
I'm curious what ATPL knowledge you're planning to apply if anything ever starts going wrong in an aircraft for real.
To the OP: the ATPLs are merely a hoop to jump through. They have close to zero practical application in the real world. Unfortunately for you, I can't imagine any (reputable) employers of ab-initio cadets will look at anyone with 8 fails in their ATPLs. That's not to say you won't be able to get a job, but I think it's highly unlikely you'll find your way into an airliner with minimum hours.