On the bottom left popout menu (the one close to where the start menu orb goes,) if you right click it, it brings up a context menu that has a ton of useful power user features. I don't suppose there is a way to keep this menu somehow when using start8? Perhaps add all of these options as part of the menu when you right click the start orb?
Also this may be beyond start8, but I'd like to know if stardock can implement it somehow: It would be nice if you could have metro apps show on the taskbar, and maybe include a right click menu to close them as well, and even include aero "peek" functionality. Also what would be nice is to have the taskbar visible even while metro and metro apps are open.