Bombadil was never a fully formed idea to start with. Tolkien himself said he couldn't explain what his purpose was in the story, only that he felt something would be missing with his removal otherwise he wouldn't have been left in.

I'm betting he was just an idea he wanted to use so he tossed him in without much regard to his nature in the grand mythos

Or their pride could influence things so that they decide to take part in this suicide run for all of the glory it would bring.

Nah... eagles are dicks.

My memory from the books (and movies) is a little rusty though, but there is one thing i was thinking about. What is the extent of Magic in Middle Earth?

Sauron was able to forge a bunch of Hyper Magical rings, alright. That Elven chick whatshername summoned a horse-shapped tidal wavel, and Gandalf shined some lights around...

Also, if Gandalf is Sauron, why did he let Saruman capture and beat the crap out of him, if Saruman was serving Sauron?!

At least a suicide run into Mt. Doom would provide the Orc Armies with a hell of a lot of roast bird to feast on.

he's a disembodied fiery eyeball, what else is there to do besides that and plot out the conquest of the known world

toga party

disembodied remember

Unless he has the orcs sow him up a giant toga for his tower.

Eventually he would be strong enough to take on physical form, and that is worth a ripping Toga Party.

Not as far as in the majority of its derivatives. As stated before, wizards here are a completely different class of beings from man; elves get some tricks because of their nature, but even then its usually the ringbearers and other really old individuals (the wave trick was actually one of Elrond's in the books). Magic among men is usually limited to people of certain descent; Aragon gets special abilities because of his lineage as the king of Gondor, and his Numenorean ancestors (basically Middle-Earth's version of Atlantis).

There's an overall feeling of magic slowly decaying over time; where the planet used to be lit by a giant glowing tree and magic lighthouses, we have a physical sun and moon later. The planet goes from being flat to round around the time the Numenorean civilization gets wiped out. The Third Age sees the last of the Elves and the Rings of Power retreating to the West or elsewhere. It's noted that Tolkien thought of the world of Middle-Earth as a sort of mythical past for our own planet, and the retreat of these more mystical elements sort of supports it.