I was looking again at
The Lord of the Rings, particularly the episode 'A Conspiracy Unmasked' and at
The Adventures of Tom Bombadil, particularly the Preface and the first poem.
In that chapter of
LotR, Merry called Farmer Maggot '
a shrewd fellow', saying, '
I've heard that he used to go into the Old Forest at one time'. (From later remarks by Tom Bombadil about Maggot this information appears to be correct.)
When Frodo decided to go through the Old Forest, Merry said, '
It sounds very desperate, but I believe Frodo is right. It is the only way of getting off without being followed at once. With luck we might get a considerable start'. (My italics)
In talking about the Old Forest, Merry said,
The Brandybucks go in - occasionally when the fit takes them. We have a private entrance. Frodo went in once, long ago. I have been in several times; Usually in daylight, of course, when the trees are sleepy and fairly quiet.
He then called the Forest '
queer'. Everything there is '
much more alive, more aware of what is going on' than in the Shire. The trees '
do not like strangers. They watch you'.
Usually this is all that happens in daylight. At night, '
things can be most alarming, or so I am told'. (My italics) He has, once or twice, been there after dark and near the hedge.
Merry finished by saying that there were '
various queer things' in the forest, or so he was told. But '
I have never seen any of them'. He admitted that '
something makes paths' there.
In terms of the title poem in
The Adventures of Tom Bombadil, Tolkien in the Preface says that it and the second poem in the collection, 'Bombadil Goes Boating', '
evidently come from the Buckland'. Both '
show that the Bucklanders knew Bombadil'. That name, added on to all his other ones, was '
Bucklandish in form'; but they had '
as little understanding of his powers', as the Shire-folk had of Gandalf's. The first poem is '
made up of various hobbit-versions of legends concerning Bombadil'.
From what we are given here, while some hobbits have gone into the Forest, it's usually been during the daytime, keeping an eye on the trees. However, most haven't gone in that far, owing to the lack of information about a willow tree and about what
William called a '
singing nutbar'.
While something is known about Bombadil, there's not enough information to coherently say who he is, otherwise Merry would have said more.
Any hobbits who knew more as a result of going far into the Forest, such as Maggot, weren't telling; so more information, and the second poem, had to wait for the account of the four hobbits' stay with Bombadil being known in the
Red Book.