I was reading your post from the beginning, and I immediately thought, there is someone else. Sure enough, as I kept reading, I saw that he has been in contact with another woman. In my opinion, don't believe the "we're just friends bit." If you have access to cell phone records, his email, text messages, take a look. Are there an unusual amount of phone calls or text messages to the same person? Suspicious or overly friendly emails? Private facebook messages? Is she his friend on facebook?
I know it's hard to believe, but I think he may be misleading you about the nature of this relationship. I know how it is, I was in denial too...for a long time. I believed his adamant denials. Until I finally allowed myself to believe that it was possible and found the thousands of text messages, tons of phone calls, and hundreds of email exchanges. At that point he was caught and had to stop lying to me in my face.
Another point, why is he asking you to move out? It seems to me that if he is the one that is disatisfied and doesn't like being around you, HE is the one that should move. Don't make it easy for him.
Also, the reason why he gets annoyed at you for cooking the wrong food, 'trying too hard', etc. is because he feels guilty as h*ll. He knows that what he is doing is wrong and he is trying to justify his behavior by blaming you. My H said the same things to me. He once commented that I was trying too hard because I offered him seconds on a meal I prepared that I knew he liked. LOL! He is going to try to rewrite history and make it sound like your marriage has been horrible all along and that he has been feeling this way for a long time, but just never spoke up. Again, don't believe it. He's trying to assuage his guilt.
Hang in there. Don't engage in any more R talks. Start GALing and detaching.
M:12yr 06/11:IDLYA 07/11:Moves out 08/11:PA disc(began in May) 09/11:Moves w OW 10/11:Breaks up w OW;gets apt 11&12/11: Touchngo w me 1/12: Comes home-PA resumes 2/12: PA disc; PA ends Today: Piecing