I've found questions about past jobs and why I left to be common enough. So I feel it's beneficial to have a narrative that paints one in the best light (ignores the negatives, promotes the positives, etc.).

>Also, even if you're aware of the question — do you rate yourself below 7, or hide the fact that you've been let go by the person rating you 7 and above?

That depends on your ethical views on lying. Personally, I don't owe companies anything and they will lie to my face about things if it benefits them (like layoffs, financial state, worth of options, etc.).