@SuzanneTF - It sounds to me like you have fallen into the trap that many calibre users face of not realising there are different toolbars of when a device is connected versus when it is not. Go back to Preferences -> Toolbars and look a little more closely at the dropdown of available toolbars, and make sure you add it to both while a device is connected and while it is not.
@Kovid - you know I think of you every time I answer that one
For your second question - no that is not possible. I think to support that it would require changes to calibre to the news feature to extend it to add such functionality (which in turn would require the Generate Cover plugin to be bundled with calibre, which it isn't).