If Mike had another job, what would it be?

He would either be writting the musical score for porno films or be a comedy writter for one of the late night talk shows.

"Do you reckon this is the blowjob scene or the anal scene?"
 
I think he would be a dude with no job, that just sits in his room and playes guitar and writes music all day or taking long walks in parks writing music there too. Enjoying like in all its aspects.

Also I dunno why but I can imagine him beeing a pothead too XD.
 
I would say photograph, or something about concert productions, one of those guys working on the stage before and after the show