Edit: Thanks to David's advice I used the Modify ePub plugin and it let me delete the cover image page on my files. Problem solved 
So I want to convert an .epub file to an .epub file on Calibre (see bottom for reasons) without creating a cover image. Right now Calibre forces me to choose a cover image. My existing .epub file does not contain a cover image so I don't want or need one after conversion.
The only reason I don't want a cover image is because Calibre creates a new 1st page in the book with whatever cover image I or the program chooses. I don't want to see this page when I open up my book. I like the way it is formatted already.
So my preferences are... 1). Find a way to convert .epub files without a cover image... if that is not possible 2). Convert .epub files without the image of the cover showing up as the first page... if that is not possible 3). Help me find a way to automatically skip this cover image page when loading the book on a Nook Simple Touch. Like would the "Start reading at (XPath expression)" help in this case? Really anything you can think of would be appreciated.
I'm just a basic user so anything you can say would help, even if it's just letting me know the impossibility of my request.
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My reason for needing to convert .epub files to .epub on Calibre is because this fixes viewing errors on my Nook. Some .epub files I find do not open in my Nook, but after conversion in Calibre they work perfectly, well except for creating an extra cover page and inserted it as the first page of the story. Which I just want to get rid of... badly.