Currently there are up to 6 clicks to reach some parts of the menu. In the proposed diagram, its a maximum of 3 to any area. "Screens" are not indicated here by the blue square buttons - I was trying to depict access points with the horizontal lines.

As to the back button, it traps you in the menu system in the current version. Forces you to click 'back', again, up to 6 times in order to get out. If it was scrapped for an 'X' out button that just automatically closed the window, it would save time. As for the use of the back button to navigate menu screens, it would even be possible with current technology (already used in game, in the new profile window) to create a slider that takes you smoothly through the screens and links them all together.

There's a billion different ways you could improve on the current design, which is years and years of people piling more features onto an initial framework that was not built to house them. The proposed image here is one such way built with the current concept of buttons and 'links' from screen to screen in mind, requiring little to no alteration of the current graphics and system in place.

If there was time and resources allotted to the design of a better menu system, it could be a lot better than it is.