As pointed out already, it's stepfather not uncle. Or brother's father when he's trying to grift based on his evil family, rather than his desperately in need family. Also, he always says 'pop', not 'soda', and spaghetti or sloppy hours are a better choice than pizza.
But this is just proof we could easily fill a randomised bingo card with far more than 25 Louisms. He's incapable of real change, and when he gets an idea like faking reddit emails, he runs it into the ground.
Firstly,
Lol no.
But my opinion on Lou's sexuality is that he'd fuck anyone, despite pretending to be asexual - like fellow lolcow Jake Alley, he seems to believe that making a big deal about being asexual and a virgin makes all his degeneracy less creepy. They're both wrong, but it's especially gross to see Lou going on about balloon tits while pretending he doesn't get off on it.
But as for pedophilia, while I don't think he's particularly into cub shit or younger kids, I also doubt he's very particular about avoiding that sort of thing. So I'd say he's undoubtedly seen/read that sort of thing, it's just not his sole focus.
As for whether he's a threat to children, I still believe he's a threat to his nephew as an abuser. Isn't he not allowed to be left alone with him? Either way, Lou actively resents him and clearly tard-rages at his family, like when he tried recording his argument with Denise thinking it made her look like the unreasonable one. So I wouldn't at all be surprised if Lou was physically and/or sexually inappropriate towards Skyler, if for no other reason than he's a fucked up bully who lashes out when he's in a bad mood - which is most of the time.