It looks like your XML sitemap is out of date. Generate a new one and make sure it is accurate. That should clear up much of that...
remove robots.txt, sitemap.xml files and generate the new one. upload it and then do verification from google webmaster tool... you will get some solution definitely. also add url removal request for 404 not found pages.
I agreed with that answer.. moreover you can click on those link and get help from google help docs..