I had a similar problem, and a similar frustration. My session would not open. But if I persistently tried to open it, it would open on maybe the 4th try, and crash soon after. I even tried the core audio fix, and I tried making session copies. Because of my stack tracks and such, import into a new session was messy and everything did not copy right.
However, here is what worked for me, and solved my problem:
It seemed that the session had got too big. I closed every program, and startup item that I could close except Logic X to maximize memory. I then got the session to open after repeated tries. As soon as this happened I did a "Save a Copy As".
Now this Saved Copy had the same issues as the original, but this time when I finally got it to open, I went to "Project Management / Clean Up..". I deleted the files. I then deleted any unnecessary tracks. I also went to the Project Browser and deleted any unused files. Basically I did what ever I could to make the session smaller. I then saved this session, and my problem went away, and never came back!
I hope that can help you, because it saved my life.