If you are running Wordpress also check what page / pages are being accessed. I have had bots nail my wp-login like that before. If that is the case harden your installation, one thing I have found that stopped it was setting a deny in the htaccess on wp-login / wp-admin.

This is a pretty good explanation, http://moz.com/learn/seo/url

If you are using the new bar, on the left hand side click the marker next to the page with the magnifying glass. From there you can highlight links.

As far as I know it cannot currently be done with schema markup. The only allowance in the standard in the product standard that Google uses is for having multiple sellers selling the same product. From everything I have tested and seen you cannot have multiple products on the same page. I would think that having products with color or size variations would consist of multiple products since they may have a different upc or mpn on them.