Well, I didn't studied from other book than Core JSF, that's why I was surprised to find questions I didn't knew nothing about, I just used reasoning and I got them right.
I didn't had any mock questions, that's why it was so difficult.
You really need to know what scope to use in what situations (request, session, view, conversation).
The syntax you need to know isn't very difficult, but you must do some practice, don't just read the book, in order to remember better.
Bottom line: the certification is relatively new, it would have been better to wait half a year or a year for some mock questions, and then life would have been easier.
I think you can read the official API for some tags and classes to get what is missing from Core JSF.