Not entirely responding to your question, but this is my favorite interpretation of Tom Bombadil:
It basically argues that Tom is actually a new Dark Lord, waiting for Sauron to be defeated so that he can pick up his mantle after the Wizards and Elves have departed Middle-Earth.
Oldest and Fatherless: The Terrible Secret of Tom Bombadil

(Dungeons & Dragons)
Rulebook featuring "high magic" options, including a host of new spells.