Hello, I know I can't even answer the first two questions and I'm not in med school yet...(too optimistic???) but I can give you a little light on what biomed is like in my perspective. Like you, I too was a bit of a perfectionist(based on ncea lvl3 study habits). For all my papers, I strived to digest/learn and memorise each day's work by synthesising my notes from the course book, lecture notes, lecture slides, and I did the reference/further readings in the textbook. Sometimes, I even added sections of the textbook to my already comprehensive set of notes. As diligent and hard-working this may seem, I regret this very much. At first, I did all this and I found that my life literally consisted of study and sleep. Period. That's not really "living". Every cell in my body felt miserable. So then I mixed this with a social life - I walked around campus as a half-dead sleep deprived soul because mixing that study routine with friends just doesn't work. Lectures were hell. SO, I ended up finding myself an efficient routine for study and this allowed me to have a balance of both.
My personal advice from my limited experience just reinforces what [4everalone/g.walker/and possibly others?] said. Read the textbookwhen you don't understand something, and you should really pour time into trying to learn/memorise those lecture slides/coursebook as a priority. You can rote-learn, like a lot of people do, but personally I find memorising easier when I understand the content first... I did some practice tests, and the slides, to my disbelief, were so much more comprehensive than I thought. So much of those past papers 2009/2010 were actually able to be done WITHOUT the textbook. There is just a lot more content in biomed compared to level 3 ncea. You CANNOT try to know every detail for everything. You will most likely "die". Even learning just the coursebook/lecture slide learning takes a fair bit of time to do properly.
Being a slow reader means you'll just need more time than others to learn/memorise content I guess. Hopefully, it't not too slow. However in a test situation, I guess this could be a disadvantage depending on how much wording is in the question? Being a perfectionist in biomed, in my opinion, is not so great. You'll just get owned.. Not procrastinating and getting on to things quickly will save you a lot of time and really it will benefit you in the long run. In a residential hall though, it is difficult at times. But really, you just need to find your own personal rhythm which works well for you and stick to it...
I hope my rant helped you a little bit.