When I started this game, teaching my kids the mysteries of the elevenplus and it was a mystery, the choice of materials was very limited.
Over the last three years this site has promoted e-papers, CDs and download CDs. Some at graded levels. A big step forward in my opinion.
Using this site I have successfully guided DS1 through the process and am working with DS2 and DD.
When we come across errors or questions and answers that we don't understand then we act as we would in an exam, reduce the number of choices make a best guess and move on.
I can understand your frustrations but am concerned come test day your child might spend to much time on an individual question, my DS2 in particular might choose to argue with an invigilator
but I will train him to carry on in the test and come home and argue with me.
Some of the questions ask for best fit and so are not perfect.
Out of interest which area and schools are trying for?
Good luck and best wishes.