I'm afraid that prep for another VI has shuffled a lot of the details from my mind. But here is what I can recall about the CRS VI...
The practice questions are not assessed, of course, but it is possible that they may be viewed by the grad team. Always assume that someone is on the other end of a camera. Personally, I find having a lot of practice questions to be great for settling the nerves, but in my experience, the longer the VI and the more questions involved, the more likely things are to flag and loose structure. You may end up drawing on the same example twice, for example, or hesitate if this was also covered in the practice questions.
There was a mix of competency, motivational questions and commercial awareness; no SJT, as far as I can recall. The prep time was about 30 seconds for a 90 second answer, but don't quote me on that.
If you're prepping for yours now, good luck!