No. Usually a guy never figures out how he got his prostatitis, but this just isn't possible. Some teens can damage themselves by squeezing at the last moment to prevent emission of sperms -- this is a cultural (i'd say superstitious) practice that's been written up in the medical journals; please don't do this, as this can cause pain and perhaps damage to the prostsate & vesicles.
Maybe but rare. Possible but rare. If your symptoms persist, see md.
No. Can have pain or soreness of the penis. Mild irritative urethritis of penile urethra.
No. Masturbation cannot cause infection of the prostate or anything else. It is a normal, healthy behavior.
If you have chronic prostatitis and you're on alpha blockers, can you do sex masturbation? And if there is an infection in the prostate?
Yes. But it may aggravate your prostatitis.