I read Piers Anthony when I was a kid, so a lot of the creepiness didn't really stick with me. They were mostly just adventure stories at that age, with the sort of gender politics you'd expect from someone of his age, the 'man is the head of the family but the woman is the real power' sort. Now I don't think he's a good writer and is way too fond of writing about sex with girls, but I thought that his strength was in his plotting, rather than anything else, because a number of his books were satisfyingly put together.
He also had a thing about getting bored with the same woman, it seemed, because a number of times his plots involved more than one woman using the same body, or in A Spell for Chameleon the trick being that the hero can only fall in love with this woman because she changed over the course of a month so he wasn't stuck with someone who stayed the same for the rest of his life. I imagine that's more of that free love hippy stuff. Also, I learned what the word 'Juxtaposition' meant because of him.
I don't think the teenage boy who ran away to his house would have been molested, though, because he was always really just pervy about girls, rather than children in general - oh, and a thing about horses, I think his family had a few, and he liked putting them as characters into his books. I get the sense that he pours all that wrongness into his books, rather than actually being an active pedophile - but that's just because I remember there was a girl who was in a horrific car accident, and as she was a fan of Elfquest and Xanth he put her into his Xanth books as an Elfquest elf to cheer her up. He certainly had a lot of female fans, younger and older, when I was reading them.
But yeah, in retrospect there's a lot of grossness there. Which is a shame, because his books really were something I enjoyed back in the day. It's like that feeling when something you loved as a kid turns out to be pretty shit, but with fucking underage girls being part of it.