Re: I was preparing a full-resolution PDF for distribution, put the wrong watermark on it and stopped the process after Step 2. This left several pages with the incorrect watermark on it. Is there any way to remove this watermark?

I would try the object select tool and see if you can select the watermark on each page and delete it. You might check to see if there is a preflight script to remove markup (the watermark is a markup and not part of the basic document).