Wasn't Vader still a good guy in high school?

eh. not so much.

For all that those angels are telling the kid not to be alone, he is alone with that man (I assume a priest). The only beings beside the man are the angels, and they're either not real or not impacting whatever's going on.

It sounds like what a pedophile would say, "I know we're not supposed to be alone together, but the angels are here and they know what we're doing so it's OK."