I've been following the thread for a really long time but yes I'd say someone making an in depth tutorial for all the rest of the users would be amazing. Having to search 50 plus pages for different info would be daunting for newcomers on how to set up mupen next and retroarch for full speed usage. I suck at writing up essays,papers, and tutorials for others to easily follow lol.
I know the feeling, I went thru both this thread and the RetroArch thread and it was quite an adventure lol. I was actually thinking about creating a Mupen thread the other day, but it seems like things keep changing quite frequently and just today m4xw dropped a new mupen64 build in the RetroArch thread. So I was kind of waiting for things to settle down a little more before making a thread.