The main problem with Kat is she has more red flags than a military parade in the Soviet Union. The big one being she apparently had a comfortable life with Subaru Man; but rebuked that to hop on the gout train, flew out a few times, and then made a permanent move. I'm open to the idea of people being able to change, but it usually comes with a huge life-changing occurrence. With that in mind, she's a trust hazard, and marriage won't change that, only enhance the damage (emotionally and fiscally) when the split happens. With Leanna, the changing point for me was watching her try to be playful with Phil while he was playing Nier: Automata. She was trying to be cute and playful, and Phil just sat there like an exceptional individual, then apologized to the chat for not paying attention to them. Which then led to Leanna pointing at his crotch and saying it'll remain a man-only zone. I know plenty of people are emotionally exceptional, but Phil is on a whole other level.
I can't tell if he's a sociopath or just emotionally exceptional. Sociopaths generally understand they use people to further themselves, which he does with his viewers. But the way he complains about his real life relationships makes me lean towards the exceptional individual side. Yes he's abusive in his own way; emotionally, and isolating the women he lives with. But at the same time, a clever sociopath could play the game better than he did; i.e. not broadcast everything to the internet. Maybe it's just something I don't see, but it's like he jumps between decent manipulator and absolute exceptional individual.
No doubt she's going to leave. She left Subaru Man for Phil, jumping across the country for him. It'll only be a matter of time till she thinks she finds something better, or says fuck it and leaves. The question is how much damage that marriage contract is going to cause Phil, and if it'll actually finish him off.