I agree with jsimmo. it's an excellent way to study. i have done it with every module. Firstly, i rewrote my notes, and then did every question possible on both exam 1 and 2 relating to that module and pasted the ones i got wrong into my book that i'm taking into the exam. the questions won't vary a lot this year, and you can basically predict what they are going to ask you. Revel, i wouldn't worry. I am making careless mistakes too, but if you employ the strategy that jsimmo suggested, you will gradually begin getting less questions wrong. At the end of the day, you are the only one who can determine whether or not you are prepared, so take no chances. study what works for you, but if you're strategic about it i wouldn't be wasting time learning the really easy info at the start of the modules - they'll only give 1-2 questions on it, and basically everybody in the state gets them correct. I'd be focusing on, for example, seasonal adjustment and transforming to linearity for CORE, purely because they are bound to ask questions on it.
hope this calmed you down a bit lol... we are all shitting ourselves though so don't worry!
peace.