Okay, I figured out three of them! For anyone else that couldn't figure it out, I'll give ya some help ;p
For the last Smilk ending, you need to start from the beginning. you need to wander the castle, but run from the blue apple. from there you need to pick up Nilly's book, answer Smilk correctly, stay, but refuse to take off the broach. Complete the next mini games correctly, then get the berry juice. From there, that will unlock the three endings I got. I won't spoil what to do, other than one needing the chocolate.
I still need help with the fourth Shadow Milk route, so if anyone is able to give me a hint, I would be forever grateful :3