I'm assuming the page map has to do with creating the companion "page" files for mapping page numbers to a physical edition of the book. I don't know if there's any publishing guidelines/specs for the page map available yet.
As for the cover image size, i believe it's looking for 600x800... bigger is too big, smaller is too small.
Just keep in mind that "warnings" are not "errors."
Just a note: some of the fonts you're using in the "Availability" section (location 10), do not work on the Kindle (or Kindle DX). They only show as ugly question marks. Most
of the fonts will work in Kindle for PC (except the one between Malti and Nederlands). The situation is the same with the Kindle for iPhone or iPad. The Kindle Previewer can be invaluable for checking these things.