I can't speak to most subparts of your question, but I can say something from experience about the part where you say that <.1 is often considered zero.
At my cancer center those of us who are considered at relatively lower risk for biochemical recurrence are given the old standard PSA tests, which are less expensive than the super-sensitive PSA tests. I think it's also an issue re insurance reimbursement. Anyway, for the regular tests, the lower limit for detecting PSA is 0.1 ng/ml. Thus, a negative test result is <0.1 = "undetectable."
That's the way it was explained to me. Hope that helps, at least a little.
No family history of PC. PSA reading in 2000 was around 3.0 . Annual PSA readings gradually rose; no one said anything to me until my PSA reached 4.0 in September 2007, at which point my internist advised me to see a urologist.
Urologist advised a repeat PSA reading in six months = 4.0 . Diagnosed May 2008 at age 56 as a result of 12 core biopsy. Biopsy report by Bostwick Laboratories = Gleason 3 + 3.
Interviewed two urologists - the one who did the biopsy and another - the latter had the biopsy slides re-examined = Gleason 3 + 3.
Then went to M. D. Anderson Cancer Center in Houston in July 2008 and met with a urologist and a radiologist. Biopsy slides re-examined yet again, this time by MDA's internal pathology department = Gleason 3 + 4.
Chose da Vinci surgery over proton beam therapy; surgery performed at M. D. Anderson Cancer Center on August 15, 2008. Post-operative pathology report = four tumors, carcinoma contained in prostate, clean (negative) margins, lymph nodes clear, seminal vesicles clear. Gleason = 4 + 3.
Minor temporary incontinence; current extent of ED uncertain due to lack of sexual partner; refused treatments for ED as being pointless under the circumstances.
November 2008 = <0.1 ["undetectable"]
June 2009 = <0.1
December 2009 = <0.1