SIE Exam For Dummies

I'm sitting for the SIE exam in a bit less than 3 weeks. I got the SIE Exam For Dummies textbook (which's been brought up a lot in this sub), and I'm currently reading through the chapters and doing the chapter practice questions. I'm wondering:

1. If this book is sufficient or do I need additional resources to pass comfortably?
2. Are the practice questions from this book representative of the actual exam in terms of difficulty?

Thanks!