These truisms are all false. Happiness is largely independent of your wealth. Studies have shown this. However, wealth does bring security and that can be worth a lot of peace of mind.
You need peace of mind to accumulate wealth in the first place. Unlikely to happen otherwise. So having more wont effect your peace of mind that much, it was likely already high. Now if someone who lacks peace of mind gets a windfall it will make little difference to their peace of mind level after a short while. They might be a little bit happier and less stressed but not by much.
I don't believe this is true. Becoming wealthy is about having a good process (i'm talking pretty meta here) and some luck. You can be stressed out and still have a good process. You can have attained Zen and still have a good process. I personally know people in either camp. I'm more likely in the former category myself. With respect to wealth and happiness, because of the luck component, it's better not to tie your happiness to things defined my money like material possessions. It's better to tie your happiness to the process, which you can control to a large degree if you are fortunately enough to be born in the right country. Otherwise, it's better to define your happiness on things you can control like your family, health, hobbies, etc.
This is a traders forum. Happiness on ET is defined by building a big fat trading account that throws off more big fat profits on an ongoing basis.
A big, fat, trading account....That sounds Yummy, yummy yummy yummy -- Good, good good good, Just like a million dollar Turtle or Salmon or Big Mac, or Cheesecake,
Having the right mindset is important before you think of making money. Moreover, imo happiness is not only making big profits but those small profits who have their contribution in making bigger profits.