I just did my PPL theory yesterday for SI- I hate them too. Motz is on the money, do the easy ones first- read every Q twice, then when you think you have the answer- read it again as most often there is the other right answer hiding! I got caught on three double whammy's yesterday and should have known better. The CASA boys write the questions not just to see if you know the answer to the question but any associated rule/law or principle that applies to it as well.
The Cyber sample exams are really good, and I came across 4 or 5 in the test yesterday that I had covered in study with them.
Your BAK will be done within your school so theres absolutely no harm in approaching your instructor beforehand and going through any area's you have concerns about. CASA has their sample Q's you can do, as does Tait, but a study text that refers you back to or explains the concept is more beneficial.
Finally RELAX!!- you're not the first and won't be the last and treat the exams as a learning exercise as well, much better to get it wrong on the ground and revise than in the air... Good luck.