Richard - no, you're getting back to the dictionary distinctions between nouns and adjectives that have been thrashed out in the ghastly thread.

The essence of professionalism is to perform to the best of your ability and with integrity and respect for your audience.

I decided I didn't want to be a professional singer because singing is what I do to enjoy myself, not because someone is paying me to do it whether I enjoy it or not!

Kitty