I call what you described above as the "skinny french fry fight". In the 13 years I was w/my H (and keep in mind we are both 34 so it really was 1/3 of our lives we spent together) the BIGGEST fight we ever had was over french fries. I bought the skinny french fries for a dinner I was preparing and he wanted the thick ones.
Clearly two sane people would not engage in such a battle over french fries. We weren't fighting about french fries though and we both knew it. It was just easier to fight about french fries then what was really going on. Funny how somebody can be so vocal about their absolute *need* for thick french fries but keeps important needs they felt not being met to themselves.
I think most divorced/soon to be divorced/separated spouses all have the "skinny french fry fight". Its sick but easier to fight about french fries, tools, CD's or *something* that is trivial because once you start arguing about the *real* stuff a [censored] storm starts. It's much easier to apologize about a fight over "skinny french fries" then apologize for the underlying reason. French fries and tools are tangible. Feelings and hurt and betrayal are not. That is what makes it tough IMO.
And I am on the same page as you about the post divorce "friendship". It just won't work for me given the circumstances my H created. I will take accountability for my part of the demise of OUR marriage but I wont be party to the crap he has pulled over the past 21 months.