Hi, I've nearly finished Part Two. I agree with a lot of what you've said, but I often find it quite difficult to tell how much of the arguments we read are Dostoevsky's beliefs, and how much just things he wanted to bring to our attention and make us think about.
For example, what Ivan said at the monastery about how the state should be absorbed into the Church seems to be close to Dostoevsky's own view, but later it's revealed that Ivan probably didn't believe it himself and was just being a "seminarist careerist". Also it's interesting how, although I've read that Dostoevsky thought Russia should be ruled through the Orthodox Church, that he seems to disapprove of some Church practises and highlights its faults. The visiting monk and the monk who lived in the apiary fasting a lot (can't remember the names) definitely weren't portrayed in a positive light.
Alyosha is very idealised - he comforts everyone and gives them guidance. I wonder if he's how Dostoevsky would have liked his son to be (he is named after Dostoevsky's son who died as a child)