Procedural Author
composer
A Skeptic person
Such a person is immortal.
Ambidextrous, ambi meaning both (abiguous) and dextrous meaning dexterity, flexibility, skillfully.
A person who robs is called a "Robber".
The person who makes a will (or 'testament') is a testator.
A Philosopher
A person who writes the libretto for an opera is simply referred to as the librettist.
A drawer.
proposal
A poetry
publisher
A person who writes verses is a poet.
A columnist...?
The word is referee.
A screenwriter
Author