TBH, I think alot of members have steered clear of this discussion. The psychodynamics of 2 people from backgrounds unlike just about anything we could ever have lived or imagined leaves a huge gap of speculation open for discussion.
I do believe Lisa felt/feels a connection to Michael, for multiple reasons. The life she led with her father, all the fame, all the drama, the users in her father's camp, even the eventual cause of death of her father. Michael and Lisa were 2 people from vastly different life realities than anything that most of us could ever imagine.
Personally I think a scenario of Michael/Lisa having an intense relationship to be highly possible, but not for the reasons most of us would have in an "average" male/female relationship or marriage. The psychodynamics are worlds apart from the typical or "normal" love match, but only because of their family/life experiences.
Could or did Michael care deeply after their breakup, very possible. Could and does Lisa still have regrets, for whatever reasons, all not completely resolved even at this point, wouldn't surprise me in the least.
Ultimately, I don't think any one of us can say with certainty just went on, what the psychodynamics were, who hurt whom to the point of no return. There will always be the Lisa haters, but none of us have walked in her shoes or life experiences. And the exact same thing can be said for Micheal. What his priorities were during the marriage, his life was highly fragmented at times as well.
Bottom line for me, the "letter" can't ever be fully solved with what little concrete evidence we have for anything, including the ultimate veracity of it's "author" BUT, I guess it makes for interesting discussion and variance of viewpoint.
jmo