Difference in Definition Between Sex & Gender

Please feel free to add your own notes and comparisons. Perhaps one day I will come back and give biblical references for my thoughts, but do not count on it.

Gender: outward expression

Sex: deeply personal, private

Gender: outward trappings, clothing, communities and customs by which to behave

Sex: requires surgery or mutilation to change; can be deformed at/before birth or later in life. Always painful to change - there is blood. 

Gender: changes by stepping into the closet, so to say. Acting. Clothing, the requirements for which may change from year to year.

I give no ruling to say that this is an absolute. But I do say clearly that there is a difference between the two, and the fact of sex and the notion of gender are mutually exclusive, though they do often correspond. But that is a different subject.

A Comparison of Poems Written 20 Years Apart

In the following I will be comparing the first two stanzas of two different poems by Joy Davidman.
I am doing this in an attempt to highlight a shift in a poet's writing that I have sensed but never articulated: that if they start off tightly wound, they loosen up through the years.

This is in no way conclusive. I have been reading through A Naked Tree by Joy Davidman (Ed. Don W. King, Eerdman's press) and I couldn't really get through it. Mostly, I couldn't sit through all the poems of her earlier years, 1930's or so. She was not in her juvenile-qualifying years at this time, she was in her 20's at the time of writing them. But there is something in the writing that is stressed and stressed-over like the first writings of a blossoming poet that wants very much to be good.

"And Rainbow Wings"

If in my dream you wore a monstrous shape,

Some unimaginable beast of death

To part my little body and my breath,

An iron dragon or distorted ape;

If your strong semblance came in lust to rape

A flesh that flowers to this consummation,

Or brought an illusory adoration,

Sleep would become enchantment and escape."   (May 1934)

The first two stanzas here are more sound than feeling: see the alliteration; feel the shape of your mouth as you read it out loud; ask yourself what tangible senses you pick up on.
The story here (and I by no means think every poem needs a narrative or plot, but please hold back your critics of my critiquing, please) is abstract. Sure, dreams are abstract, but the senses are so unattended to that I do not know where to place my attention. Should I be thinking about the ape, the flesh, or the escape? Why does my mouth find distaste in saying "illusory adoration"?
This poem gets me nowhere except impressed with how things sound next to each other. 

I do not want more of this poem.

Now let's look at the next poem.

"XXXV"
Poor child, who read a book of magic once,

And tried such games as walking on the waves,

Distilling essences of stars and suns,

And conjuring dead women from their graves

To skip a sarabande about you! When,

As children will, you wearied of your play
And would have sent them to their holes again,

How sad to find they would not go away!"   (May 9, 1954)

Now here we have a story. There is progression in the reader's mind from child with a book, child at the ocean, child under the stars, child in the grave yard. The settings are clear.

In eight lines I have a history of the speaker's subject: a child who was once enthralled with magic found in a book, played child-like with it, only to have a haunting consequence - be it either wisdom learned too soon or longing for the first initial rush that cannot be again played out.
The sounds of this poem, as well, are less chalked-full of syllables, but instead flow like a casual sentence. 

Whatever it is, I want more of this poem. 

The first poem seems too contrived for my liking. I feel that the speaker merely wants to use the "poetic" words they find power in rather than crafting a cohesive piece.

Has anyone else noticed a trend from strained to natural in poetry or writing? Or any other shifts in an author's style through their career?