Thorough and thoughtful post, Rick.
There is on more possible trigger for low libido after prostate surgery: decrease in testosterone.
Dr. John Mulhall told me that the medical community doesn't yet understand the connection between the prostate and testosterone. He said that several of the surgeons at Sloan-Kettering routinely measure testosterone in men before surgery and then again awhile after surgery. While many men show no change in testosterone level, a meaningful percentage of men do show a significant decrease in testosterone. Again, the reason for testosterone decrease after prostate surgery is not understood.
Testosterone replacement therapy for men who had prostate cancer is a touchy subject. Dr. Mulhall believes that TRT is fine for men who have zero PSA after surgery (and claims that he has treated 150 post-RP men with TRT, and not a single one has had lost their zero). Dr. Abraham Morgentaler (Harvard Medical School and Men's Health Boston) is also treats men with TRT after prostate cancer treatment. Even so, many doctors are still very hesitant to intentionally raise the testosterone level in men who had prostate cancer.
I recommend that every man with low libido have their total and free testosterone tested, especially men who have had prostate surgery.
For more on the topic of TRT after prostate cancer, I recommend Dr. Morgentaler's book
Testosterone for Life and Dr. Mulhall's book
Saving Your Sex Life A Guide for Men with Prostate Cancer.
-Gedman