Tested under mavericks, I found two problems with the fullscreen shortcut.
First, when triggering fullscreen mode the window is maximized to occupy the whole screen, which is NOT fullscreen (at least in mavericks, windows can be made true fullscreen, without a status bar, etc.).
Second, after triggering fullscreen (which is only maximizing the window) the shortcut to center the window is not working anymore (I expected center to either unmaximize the window to the previous state, or to simply center the window in the screen with a fixed margin).
PS: I realize the second issue might be intentional. In the case where the first issue is also intentional, I would suggest renaming from fullscreen to maximize or fullwindow, and perhaps adding real fullscreen functionality.
Both are intentional. Renaming the fullscreen action is probably a good idea! I'll create a separate issue to track that.