It always seems to me like he's saying "you're all giving me way too much credit because my narrative is straightforward and much less creative than you're all speculating."

Joel definitely doesn't want to end the marriage. Did you see that wistful look as Julia left? I think he's waiting for Julia to do some serious atoning (and should be). Julia wasn't even blaming herself for the problems until Ed set her straight.

People who feel guilty and whose lives are spinning out of control? Once Joel talked to her about it she clearly saw she was wrong and left even though the situation hurt her.