i think you're discounting psychology, and i guess this because you put "demonstrable" in quotes. psychological harm is harder to prove than any other disease, but it is real.

adults understand relationships better. they have been exposed to higher education, have read books with insight into relationships, and explored their sexualities variously.

even in adults-only relationships, there are occassional freaks. in an adult-child relationship, the adult would easily overpower the child if s/he were one of the sadists you describe. adults know to dial 911, children are regarded as heros on the news if they do.

do you really think more than a very, very rare lucky relationship of pedophilia could ever completely work? loving, marital-type pedophilic relationships will never occur on a large-scale basis, ever, this generation or ten from now. the random pedophiles that chance favors, gods bless them, but they are far between.

i'm not an anti, but the only pedophiles i'm in favor of are the glorious ones who somehow find complete, free fulfillment, and harm no one. us lessers will swell up in the shadows but probably keep getting stomped down.