I took the MCAT in July and scored 9 on the BS section.
I didn't study ochem, and my knowledge on the subject was very rusty.
That's being said, I had two passages and around 3-4 discrete questions devoted to ochem.
From experience, I can say that physio is more relevant on the mcat. However, you shouldn't count on that. I know people who had 3 ochem passages and non-physio related ones on their test. Besides, ochem is a requirement for med school admission.
Bottom line, whether you are aiming for 8 or 15, you shouldn't take the mcat unless you're ready. People say shoot for the starts to get the moon, and I say shoot for the stars to climb the tree.