Ah the old Bombadilian origins chestnut! Always a favorite, and there are some real doozies in there. From Letter 144 to Naomi Mitchison:

Tom Bombadil is not an important person – to the narrative. I suppose he has some importance as a 'comment'. I mean, I do not really write like that: he is just an invention (who first appeared in the Oxford Magazine about 1933), and he represents something that I feel important, though I would not be prepared to analyze the feeling precisely. I would not, however, have left him in, if he did not have some kind of function. I might put it this way. The story is cast in terms of a good side, and a bad side, beauty against ruthless ugliness, tyranny against kingship, moderated freedom with consent against compulsion that has long lost any object save mere power, and so on; but both sides in some degree, conservative or destructive, want a measure of control. but if you have, as it were taken 'a vow of poverty', renounced control, and take your delight in things for themselves without reference to yourself, watching, observing, and to some extent knowing, then the question of the rights and wrongs of power and control might become utterly meaningless to you, and the means of power quite valueless. It is a natural pacifist view, which always arises in the mind when there is a war. But the view of Rivendell seems to be that it is an excellent thing to have represented, but that there are in fact things with which it cannot cope; and upon which its existence nonetheless depends. Ultimately only the victory of the West will allow Bombadil to continue, or even to survive. Nothing would be left for him in the world of Sauron.

He has no connexion in my mind with the Entwives. What had happened to them is not resolved in this book. He is in a way the answer to them in the sense that he is almost the opposite, being say, Botany and Zoology (as sciences) and Poetry as opposed to Cattle-breeding and Agriculture and practicality.

I would surmise that JRRT himself had not really defined what TB was, but one of the commenters (on page 6, I think) said something about "time and nature," which might fit with what JRRT wrote. Frankly, I like the ambiguity of TB.

But really? It's your fabulous crack!fic that made me LOL this morning! That's great!

But! he's also Yavanna's dealer. He provides all that she needs to keep Aulë rhyming and capering and complacent. Pretty dysfunctional, when you think about it.

AH HAHAHAHAHA!