In my opinion this is due to a sort of “slang” that comes from older version of GS. If you find something strange, I guess you should open a thread and inform the team so they will update the manual. I am honest, I hardly ever use the manual because using the app almost everyday helps you to know it better
Maybe yes, it happened also to me. Were these listings listed before? I mean, are you relisting items that you already put over ebay, or are those listings completely new? If, as I suppose, this is a relist, sometimes when GS has not fully updated listings info send you this warning, but it is yellow and not red, it means you can list anyway. Just do not pay attention to that warning.
And I am glad if I can help you somehow 
Welcome, and no Spain, I am writing from Italy!
Have a nice evening
Federico