Excellent post, Coach!
The only thing I'd like to add is that the calcification process of the pineal gland begins during puberty and progresses steadily with age.
I've done quite a bit of research on this, and believe it's no coincidence that hGH is another hormone whose presence declines with age. Growth hormone secretion is highest during delta wave sleep. It stands to reason that the shittier our sleep cycles, the less hGH we will enjoy.
Someone did studies on the cadavers of 70+ year-old men and found that their adenohypophysis contained ample amounts of growth hormone, despite the fact that men that age have very little circulating hGH levels. That suggests that their pituitary gland is still "manufacturing" the hormone, but it's not being released into the body.
IMO, it is quite reasonable to attribute the hGH deficiency to shitty circadian rhythmicity...which is related to advanced aging AND the accompanying melatonin deficiency. Hence, improving sleep architecture (via the natural hormone melatonin) "may" help support optimal levels of circulating human growth hormone levels in humans.