It sounds like a combination of a bad law and bad side path design and construction. If they are currently not enforcing the law I might be inclined to leave well enough alone. But the hazards you point out on the side path (driveways etc) are serious and should be addressed. You may want to document the hazards with photographs and models of better design standards to demonstrate the inadequacy of the path. I'm sure that before the city would spend the money to rebuild the path correctly they would be inclined to shelve the law. By chronicling the hazards of the bike path and submitting them to local legislators and appropriate city departments you may give some future cyclist a legal leg to stand on should they be involved in some stupid litigation due to an accident on the path or while riding on the street.