Hi,
My 2 cents and well worth it...
Your headlights will be fine if you have your mechanic install a relay so that the headlight current is not going through the switch. If your mechanic doesn't know how to do this, get another mechanic.
Between the Cord, my 37 Buick, and my past-owned Lasalle, I often had folks ask me to "drive weddings," offering cash under the table. I avoided them like the plague. The liabilities are near infinite, as are the costs of insurance and meeting livery vehicle standards and licensing. Do your research carefully before you jump into a business with a car that is not intended to be in your business.
--Tom