Fill - everyone is different and how they best learn varies. We make use of DSCtraining as an option for students with us - and all feedback is very positive. Keeping that sentence in mind, we have found a few students 'learning the questions' as opposed to 'learning the material'. Our advice is that a good study manual is invaluable and should be as a minimum a constant reference through your study.
Regards the questions and answers on the site - there where some historic wrinkles, but so far as aware it should have been showing all correct answers for all the main question banks for quite some time now. Steve of DSCtraining visits on here and is easy to contact via the site details or people can funnel any queried answers to me and I'll pass them on.