"Lots of people work without licenses and without training. As long as they do not mislead their consumers, and can do the work, I won't condemn them..it is far better if they do have licenses and ongoing education and good training to start with..."

I've hired many a plumber in the rentals I managed and believe me, I want a licensed one. If a plumber botches a job, whether through ruining a wall or breaking a water line or just plain not finding a leak, I want recourse. I also want the person to be bonded or at least bondable and I want him to have insurance.