Would such removing of licenses of the above occupations impede the effectiveness of their abilities to carry out their jobs? I would like to make sure that not requiring licenses will not result in non-properly trained employees.
I would say generally no. There might be a few more inexperienced beauticians or hair braiders, but the market is usually good about sorting that out.
I'm not even sure what training coffin salespersons or interior decorators or florists and the like receive that might make them better or worse at their job. With barbers and piercings there is a hygiene aspect to the training, but local regulations on cleanliness can just as easily prescribe health code standards that function the same as paying several hundred dollars and a year of your time to a private group that teaches the exact same information. Most localities which issue building permits will still need to inspect a swimming pool regardless of whether or not the workers paid a grand to become certified. And there is a Circuit split right now on whether or not requiring people who walk and talk (tour guides) to take a standardized history test and pay to hold a license is unconstitutional under the 1st Amendment. SCOTUS recently struck down a NC law prohibiting persons without a dental hygienist license from providing teeth whitening services.
I think any decline in quality would be minimal, and it would make it easier for many of our brothers and sisters who have been left behind by the emerging economy to carve out a service job without having to wait a year or more and pay a fair amount of money to private courses just to become eligible to try and find a job. There is no need for the girl at the nail salon to have 100 hours of government mandated classes just to pursue a career.