All of those quirks would be intuitive to a mac user, but to the parent's point, they are unintuitive because it works differently from Windows. Before the green traffic light went full screen it was Zoom, not maximize. It fit the window to the content, the logic being why would you cover a huge display with white space just to read an 800px wide document. Fullscreen breaks long time macOS behavior, throwing that window over to its own space and breaks the desktop centric design.

Likewise with the red traffic light. Windows couples process lifecycle to the window lifecycle. macOS separates process from the presentation, the paradigm is a desk full of papers, and so documents are separate from their application, the app remains ready to open another file when you close that specific document.

I'll give you app installation via drag and drop, if the background image of the .dmg doesn't have that arrow queue then you're right, it's pretty unintuitive but even then, the idea is you don't have to install an app on macOS. They are just bundles, you run them from anywhere. Dragging and dropping into /Applications is totally optional.

Windows has its fair share of unintuitive behavior/arbitrary quirks too that's overlooked because "that's how it's always been." What's intuitive or not still just comes down to muscle memory.