I would only seat the 3!!!!!! and if you really want to know more about the other subjects just read the books, you will find lots of JAA questions at the end of the chapters as you probably know.
I am personally going through the JAA ATPL(A) and would never seat them volountarily if I didn't have to.
However this is only my opinion and everyone should feel free to do what they think is the better choice.
Fingers crossed for tomorrow(I am sitting Instruments and FLT PLN) and wed (MET)!!!!!
Cheers
PI