Hi!

ad 1) For sure it's just an educated guess without having had a coaching session with you - it sounds like you are taking down too many notes which you would remember without putting it down on paper. So try to distinguish between some specific facts (which might be worth noting down, particularly numbers..) and the narrative of the case outline (which you will remember without your notes as well).

ad 2) If you ask me for a rough guess, I'd say that in 9 out of 10 cases you also get in McKinsey cases some time to think about your structure (although for sure not a couple of minutes!) - since the first question oftenly is something generic like "How would you go about structuring this issue for the client" etc. However, it makes sense to also practice a case scenario in which you don't get any time for preparing your structure upfront, in which case you will need to develop your structure on the fly while discussing it with the interviewer. At the end of the day it's not that much of a difference, it's just not thinking about the structure in silence, but walking the interviewer through your rationale and thoughts in real-time.

Hope that helps!