Re: closing apps at top right of screen
Actually, the drop down Title bar with the X in the top right corner was added in Win 8.1 update 1. It does the same thing as dragging the top of the app to the bottom of the screen. The app then goes into hibernation, where it is no longer running but still has a footprint in memory so that if you open it again it will load quicker.
To fully exit an app in Win 8.x, you need to drag it to the bottom of the screen and hold it for a second or two until it flips. When it flips, that means it has been totally removed from memory. Another way to fully remove an app from memory would be to open Task Manager and kill the task but the drag/flip thing is less brute force.
I don't use Modern apps on my laptop that runs Win 8.1 but use a few on my tablet. People that don't switch back and forth between Windows PCs and Windows Tablets can't see the beauty of an OS that works well on both platforms.