Regarding Ron. No, I don't think that's out of character at all. Through the series, Canon!Ron was a bigot, a jackass, sometimes with a useful observation but mostly serving as the bigot-relief simply because he was beyond ignorant and unable to imagine a world beyond what he knows. And his world is really damned small. He's good at hating what he's told to hate. He wants stuff, he's jealous and envious and abandons Harry and Hermione during the horcrux hunt, only coming back when it served his own ends, not theirs. There's dissertations on why Ron is a git. So him dumping a woman who makes him feel inferior (Hermione) and has more ambition than Percy... it was a foregone conclusion. Much like Harry doesn't belong with Ginny because she doesn't know or care about the Real Harry, she loves the Image. Ron just wants to have an easy life and play/watch quidditch, visit the pub and keep a few mistresses for "sporting". He wants babies and his mother's cooking. He'll marry a bird who gives him that, and will be content with it. Hermione? Never. They were a terrible couple. He hurt her almost from the outset, and she told him he was wrong with the first words from her mouth "I don't think that's a real spell".
And another thing. Harry and Hermione are a bad couple too. Shock! Their mental injuries from their childhoods are too traumatic for them to be able to live together. Its been said that Harry wants a family, and maybe he does, but that's not what he needs. He needs PTSD therapy, with war veterans and a seriously talented mental health counselor. Only after his head is straight should he entertain taking a wife. The Harry in this story is OOC, its true, but this isn't a serious story. Its a light romance and some humor. The real Harry would be physically injured, shell shocked, and probably hospitalized after fighting Voldy to death. He wouldn't be in school chumming it up in good humor and mocking Dumbles for kicks. In this context, OOC is fine. This Harry is mentally healthy, and Ron is his usual self, an idiot.
Hermione has been deceiving herself, just as Ginny has, convincing herself she'll be happy if she attaches herself to one of her friends because she's aware of the loneliness which is looming with graduation. Hermione has alienated the wizarding world by the wrong blood and being too damned smart, and rubbing it in everyone's noses for 7 years. She's the kind of girl to get Nobel prizes and go on book tours and TV to keep rubbing people's noses in it and wonder why she doesn't quite get the respect she's after. In her way she envies Harry. But its a different envy from Ron or Ginny. At least she knows Harry, and in most stories she doesn't play for him because the smart part of her knows it would hurt them both. Hermione isn't suited for relationships because she hasn't figured out people enough to get along with them. Until she learns psychology and human dynamics, she's going to be alone. That's her reality. Books and knowledge are a crutch for her problems with people.