Into the Wardrobe

A thoughtful engagement with this issue can be found in Patrick Curry's Defending Middle-earth. Check the index for "race, racism." One scholar, whom Curry cites, puts it well, I think, affirming that the appearance of racism in TLotR is deceptive "not only because in his non-fictional writings several times repudiated racist ideas, but because...in his sub-creation the whole intellectual underpinning of racism is absent." (p. 42)

See also Tom Shippey's work, especially J.R.R. Tolkien: Author of the Century for dealing with other such dismissive (and inaccurate) labelings of Tolkien (i.e., "fascist," "classist," etc., etc.)

By the way, I find that such labeling is often used as a quick excuse by those who don't want to have to do the work of engaging with a piece of writing on its own terms.

See also Tolkien's statement, "I have the hatred of apartheid in my bones" from his Valedictory Address at Oxford (published in The Monsters and the Critics and Other Essays, p. 238).

See also Tolkien's searing response (in 1938) to a German publisher who wrote to inquire of Tolkien on what they would have understood to be the question of his racial purity. (Letters, edited by H. Carpenter, p. 37-38)

This is all I have time for now. Hope that it is helpful.

Best regards.

As far as Tolkien not putting more girls in LOTR, consider what the Fellowship was up to! There's a long journey on foot, starving, being shot at, and then there's a war with slobbering, hungry ogres who would love to grind your bones to make their bread.
Here's one girl who would rather skip that combat mission! Especially back in Tolkien's day, women did not go to war as they do today.

Sidenote: A 23-year-old American female soldier just won the Silver Star Medal for courage in combat in Iraq. So cool!

Also Tolkien and Lewis (and the rest of the Inklings) were many times uncomfortable in the presence of women. They prefered the Oxford professors' rooms or the Bird and Baby. They were used to having only the company of men, without women, especially during their years at war and in college; so it is natural that their books should reflect that.
That was actually a point of conflict between Tolkien and his wife: She was jealous of all the time he spent with the Inklings.

The bonds and closeness that those men had is so lost on today's people. Tolkien was recreating that band of brothers in LOTR.