Sexual alchemy is not an advanced course in sex. It is an advanced course in Qi-Kung or body qi yoga. If you do not know about energy flows, and cannot flow energy during your regular daily practices, then this advanced form will have no meaning. Its like reading the Kama Sutra thinking it is just a book on positions.
In addition to the physical aspects that you talk about, I would also like to see much more talked about with energy and spiritual aspects.
Such as when you copulate, you are sharing the energies of your base chakra. This is also where your physical world problems are. So, you are sharing all of your problems with your partner.
However, as I have said above, most people in the west don't even believe qi exists. And those who do know it exists, few actually work on it. Most would just excuse any teachings on this as silly or "not something I need."
Currently, in The U.S. sexual education is required class in high school. But, the way its taught seems to lead to all kinds of problems. Probably the biggest problem is the oversexualization of media, and then teaching kids that what they should do is to ignore their sexual desires. Which usually creates a bad feedback loop.