Not really, no. Love and attraction are different things. You don’t need to be attracted to someone you love.

Unless you find your partner unattractive, I don’t see how sex could meaningfully change

People are good at picking up social cues. That’s probably what you’re referring to. Humans are social creatures, after all. Also, people are trash at picking up social cues, so you’re probably also missing a lot of cues.

That sounds like a really bad idea. Your sense of how common those relationships issues occur is warped. People don’t generally go into relationships trying to exploit someone. You’re going to cause issues (moral, logistical, and practical) with your plan, all because of a concern that’s not likely to happen.

That’s the vast majority of humans. We are a monogamous species, after all. When you see “alpha males” on the internet, just be aware that they’re grifters that want your money. And the best way to make sure you keep giving them money is to make sure that you stay single and unhappy.

Can’t help you there. I can at least tell you that enacting your plan in question 4 is going to lower your chances of finding a wife to 0.