"Okay - I just wasn't sure if you were meaning "legally" prepare. Although I have done my research here too."
Good for you.
"He'll still do things such as call to ask if I want something while he is out. If he is getting a cup of coffee, he will get me one. Things like that."
Don't place a tremendous amount of value in this. I say that but I want you to look at why he is doing those things. I am of the opinion that the WAS did not wake up one morning with the intention of hurting you the way they do. At the very least he is being "friendly". People will show you how to move closer to them.. if you are paying attention.
"once he initiates conversation, to feel free to talk about random stuff."
Yup. If you want to just talk.. cause you are bored or something.. feel free to break the ice. There is no "hard rule" that you can't talk to him. Just don't let the situation (talk) digress into a R talk. Again using your perception of things and using words that don't point the finger will help a lot here.
"Do you think MC is beneficial?"
It can be. It can also be more of the same for the WAS. If you want my personal opinion from what you are telling me I think Laurie may be a better mentor for you than a MC for the both of you. Again.. that is a opinion of a random guy sitting on the other side of a keyboard.
"Maybe I just have to learn how to respond in the MC session better."
So you should "prepare" yourself when you "see" something coming?
You are doing fine.. just keep "looking" at what is going on around you. Life has a funny way of pointing out things you are missing.
Relax Eat Think Act normal React.. Smartly. Do something different. Emulate. Do Work.