Is the ultimate solution to all these marriage issues a 'stateless marriage', basically a private ceremony but no documents? I want to invest (in the long term) in a family with two kids, but do not want to give any woman that much power over my income (especially since I'm on my way to an MD).

If she cheats or threatens divorce bc feelz, you can laugh in her face and kick her out. This will only work initially, however, if you are high value enough (relative to her) that she feels a stateless marriage with you is better than a contract with some bum. Ultimately, however, it completely changes the power dynamic of the relationship (she walks on a tight rope instead of you).