1) I took physiology and biochemistry in 2011 so I don't know if it really helped me that much. But I did a lot of bio and biochem courses after and I think these helped me keep a baseline of knowledge if that makes sense.
2) I used DAT Crusher (paid membership so read all the material twice and did all the practice tests), DAT Bootcamp (no membership so used all the free material), and watched two videos on Youtube for Gen Chem (5h in total).
3) The complete bio notes (Nicole's notes pro) on DAT Crusher may be sufficient. If I did not understand some concepts, I used Google lol
4) I watched all the videos on DAT Crusher before carving. I carved my first soap while watching the videos (I followed every step) - it took about 1h. In total, I carved 12 soaps (2 packs from CDA) and scored 23. So you don't NEED to carve 30-50 soaps to receive a decent score. It really depends on you. I know I could have scored higher if I practiced more, but I ran out of soaps and didn't have enough time to order more. After every soap, I went through the evaluation criteria and really tried to understand what I did wrong. I spent about 20-30 minutes going over my soap.
5) Nope, no orgo on the Canadian DAT.
6) Same as first question, I took first year bio in 2010 and did a lot of upper courses over the years so I can't really answer this question.
I'm sorry I can't be of more help. If you have more questions though, I'd be more than happy to answer. Good luck