My family and friends who are normally part of my writing projects keep trying to talk me out of it. Somedays I'm still committed and feel like it's something I have to do. Other days, I realize that even if I go through with it

1: No one else will like it.
2: I probably won't even like it.
3: No one else will probably even read it.
4: I will have wasted my time.
5: I will probably never finish it.

With regards to the cooperation aspect... my negatvity one the subject has convinced me that my ideas are mostly so far out of line with other people's ideas that any cooperation would lead to compromises I wouldn't be happy with. Sometimes creative compromises lead to strength of screenplay. Sometimes they wreck it.

On a few of my other screenplays that I've worked on... I've had writing partners but I had to establish a clear hierarchy which some of my partners didn't like. I think I'd be okay with as much as a 60%/40% split. But since it's my story, I get veto power. Former writing partners wanted 50%-50% which I think for me was just too much abdication. I have worked with people on their scripts, and see myself as an advisor and consultant more than a "writer" and therefore yield to their creative choices.

Anyways... I'm just rambling now. So I should stop.