About the best friend

Charlie is writing to someone he overheard a girl talking about, as he got the impression that this person would be a good listener. They're not actually friends, he stays anonymous and doesn't include a return address. We don't even know if this person actually reads the letters.

Did you watch the deleted scenes? You can meet his best friend Michael (who was real) there. I have the shooting script and there were a few other bits with Michael cut out, including flashing to his funeral (as well as Aunt Helen's, which is included in the final cut) and a few bits of him in the breakdown sequence at the end of the film. To me, Michael is as big of a mental issue to Charlie as Aunt Helen is at the onset of the story, especially if you've read the novel. Michael was largely dropped because the author/director felt movies don't have room for two ghosts in flashbacks, that it became confusing and had to go with the aunt, as she was clearly the more detrimental flashback story overall.

Did you watch the deleted scenes? You can meet his best friend Michael, who was real, there. I have the shooting script and there were a few other bits with Michael cut out, including flashing to his funeral (as well as Aunt Helen's) and a few bits in the breakdown sequence. To me, Michael is as big of a mental issue to Charlie as Aunt Helen is at the output of the story, especially if you've read the novel. Michael was largely dropped because the author/director felt movies didn't have room for two ghosts in flashbacks, that it became confusing and had to go with the aunt, as she was clearly the more detrimental flashback story overall.

Fun fact: You also learn Susan, the girl who won't talk to Charlie anymore, was Michael's girlfriend. She got popular after Michael died.

It was a real friend who tragically died.

For me, the 'Dear Friend' stuff works as a journalized entry method of writing to someone/anyone, instead of Charlie having to further internalize things & write to & for himself.
It's been a while, yet I think the director mentions on the commentary that the Friend is really anyone, & probably us the viewer if we so choose(?).

As for the deleted Michael scene, while it amps up the Susan cutaway moment in the caf, the way it's played seems like Charlie is more a secondary character in that scene, in the room the 2 of them. Seeing that scene after having watched the film 3-4x, it felt tacked on. Probably best that all we got was the 'he shot himself' line, while he was stoned no less- i.e. straight & sober, Charlie'd never bring him up let alone with other ppl.

...top 50 http://www.imdb.com/list/ls056413299/