Hi missus, one of the problems is that many men have very few or even no symptoms, even with late stage cancer while others have signs which could be down to a number of causes. Urinary tract infections and cystitis / burning on urination are not indicators of PCa. As you now know, loss of ejaculation is an indicator but lots of men would not be happy to mention that to a doctor.
My husband had difficulties urinating from the age of 35, multiple night-time loo visits and sometimes extreme pain in what we now know was the prostate area. However, thorough tests at the time suggested that his problem was with the bladder valve and sphincter, for which he took tablets until he was diagnosed with PCa at the age of 50. His PSA was normal. Since treatment (RP, RT & HT) he has no problems weeing at all and rarely needs to get up at night.
I can't think of any signs or symptoms that are only applicable to younger men; although we have on occasion had discussions on here about indicators that people feel in hindsight might have been relevant I don't recall anything cropping up that isn't already well documented.
What a few of us do feel though is that there should be better training for GPs - it does exist but doctors aren't forced to attend or take any notice of the prostate cancer risk assessment guidance. Too many, it seems, still believe that PCa only happens to old men and/or are reluctant to agree to relevant tests. On the other hand, there are also some great and knowledgeable ones - it seems more men are now being diagnosed in their 30s & 40s.