Are you adding oils to your BS wash? When you wash with that, are you doing the ACV rinse?
Oily hair means your scalp is too acidic. ACV is an acid. If you are using it, stop. Try washing with JUST BS for a few weeks. The oiliness should go away. Wash like that a few more times. Then VERY GENTLY reintroduce the ACV mix 1 capful of it with 1 gallon of water. Only do this once a week. The other times you wash, don't use any ACV. If you don't get oily after a couple of washes, do the same thing twice a week. If, after another couple of weeks, you still are dry, do it 3 times a week. If you still stay dry after a few washes, you can raise the amount of ACV a little bit 1 wash at a time.
As for the flakes... Have you tried Teatree and rosemary oils? Teatree is great for dandruff. It would probably help you too.
But I know Eagle will say it, so I will too. Have you tried the soaps from dreadlockshampoo.com? They have a teatree shampoo that has worked wonders for others in your same spot. You may want to give that a try instead of the BS wash. Most natural shampoos are too conditioning and have too many oils in them. That could be what is causing a lot of the issues