i was with him until he made the claim that valjean was in love with cosette. he used the facts that he's protective over her and hates marius as evidence, but 1) valjean is protective of her because he's literally on the run from the law and cosette has had a rough enough life as it is and 2) everyone hates marius. and cosette was literally all valjean had and he didn't want to lose her. the book also EXPLICITLY says that valjean was NOT in love with cosette, and loved her only as a father would.
it's really not that deep: there's no "incest motif," you're just a freak. you can pry this WHOLESOME father-daughter duo from my cold dead hands