I just wanted to add something, about the ashes, Laureen and Ennis...
I too think that Laureen had worked out, if not before, at least after Jack was murdered, that he was gay....and once Ennis phoned her, she finally knew who Jack's true love was....
The fact that she had buried half of Jack's ashes and was in favour of Ennis taking the other half of the ashes to Brokeback, was a reflection on how she felt her life with Jack had been......that she had one half of it, and Ennis had the other half.