I was self employed for a while but it didn't turn out to be the dream life style that I wanted. As you said you will be a bit out of sync with others that have 9-5 jobs. Further more it was hard for me to keep good routines. 

Self discipline is not all that easy as it is hard to kick your own butt I guess. I think to have a main job but other projects on the side is really good.  You have many channels that leaves you options and that is the ultimate freedom