Both parties should contribute equally.
That being said it's a grey area. When I was out of a job and my bf worked 12 hour shifts, and came home exhausted and defeated, I didn't mind doing all the work in the house. He did the same thing when I was working and he lost his job. Etc.
It's more like "I can do this if you don't have the time/energy" and less like "I am required to do this because he is required to handle finances" though. Every relationship is different so this would be better answered in relationship_advice, with context and background explained
You don't believe science. Science is the process of understanding and learning about the universe. There is nothing to believe. If you agree you agree, if you disagree you prove otherwise. No dogmatism, rituals, beliefs, traditions are present unlike religions. So apples to oranges.
You can also choose to understand science if you invest enough time. You cannot, for example, see a god if you work hard. Again, apples to oranges.