Great post. I would say if you've got things in place don't even wait until you're comfortable to take that step.
If you're looking to make great living on writing alone, I strongly recommend looking into freelance copywriting. The "art and science of selling through the written word."
It's what I do. It's one of the more lucrative writing careers, always in demand.
If you want to know more about that I can tell you where to start.
Meanwhile I'm rooting for you dude.