I'm not sure about the EK FL's, but I do have the TBR ones since I'm taking the class. I think if you're not in the class you can only purchase CBT's 1-7. Anyway, they do have answers and explanations, and they are quite good if you ask me. The sciences are great on the TBR exams. They're really tough and really make you apply concepts in ways you may never have thought of before, and I think that'll really help on the actual MCAT in case there's a wacky passage or two per section.
As far as scoring, there is a curve provided for each test separately. There curves are a bit generous compared to the AAMC curve. On TBR CBT 4 I got a 43/52 on PS which scaled to a 12, while on AAMC 7 I got the same raw score which ended up being a 10. I think its because the TBR tests are supposed to be more difficult.