1. Yes it is mandatory, you don't get to choose between the normal exam & the CyberLive exam.

2. It's a bit more than simply entering a command. You need to accomplish the task, so you'll need to enter a lot more commands/use different tools. The practice exam will be similar, so you 'll get a taste of how the CyberLive questions might look like in the real exam.

3. I took like 5 days off to prepare for the exam. Redoing the labs like 3-4 times each, reading the books at least 2 times (I did read the books a lot whilst doing the ON DEMAND course as well), reviewing the tool usage index etc.