So what I'm getting is, bitterness from being passionately gay in a homophobic society turned her former love from being a complete asshole (which I assume comes naturally to him) into a complete monster.
...That's actually surprisingly believable.
Her father, less so. Well, men like him exist by the boatload, but he's a caricature here.
But the commentary on her cousin, alas... 100% accurate to life as-presented, distorted self-perception of "neutrality" and all. The placator who is happy so long as no one's loudly upset, who wants everyone to be "happy" but hasn't been able to distinguish between helping someone and getting them to be quiet; who participates in the normalization of abuse while thinking they are doing a great thing. Ugh. Painful to watch.
The story being what it is, I'm assuming he may or may not turn out being even nastier, of course, as the plot may require.