A few questions about the Maiar

[Michael Martinez]

I think you're confusing Ea and Arda. Ea is the universe and is far, far older than Arda, which encompasses Middle-earth. Arda began as a single world, but eventually the Valar created the Sun, the Moon, and Venus, and Iluvatar divided Aman from Middle-earth, making Middle-earth into the round and inescapable Earth where we now dwell.

Tom was an aborigine of Middle-earth, possibly of Arda. His memory of Melkor coming from Outside is probably of Melkor's return to Arda after the Valar had settled on Almaren. Tom should have been alive by then.

I don't believe it was his purpose to guard trees. I think he was there to help the Children in ways the Valar could not be expected to. He was older and wiser than Elves, Dwarves, and Men, but he probably had no direct, personal knowledge of Iluvatar or what lay beyond Arda. So he was in a way like an elder sibling, but not so far beyond the Children in experience that he represented a true danger to them (as Melkor and Sauron did).