In a nutshell, Mendix is designed for data-driven applications. We're really good at business logic and easily handling (large amounts of) data. That's why you see all widgets built around entities. There's almost always a context in which you want to apply logic, and binding widgets to these entities enables you to do that.
That being said, I understand that this feels a little weird if you're coming from a RoR/django (or similar) world. It takes a little getting used to, but after a while it feels like second nature and you see the benefits.
As to your other question, that's another question :) I'd open a new topic so that the discussions don't get mixed.
You can quickly model an admin portal with a TextArea entity, for example, to easily create/modify the text for your web pages and some more generic entities to store any responses (sounds like you'd have some sort of form if you are using radio buttons; you can also use the values of the radio button selection for dynamic forms). The most effective use of your time would be to sign up for the intro to Mendix class (3-day training). Also check out some example templates/projects in the Academy section of the Mendix App Store.