I see a Pinterest button with a heart on it. What does it do? What benefit do I get when someone clicks on the [Love] button on my board?

We sell 1000s of audiobooks and get our cover images and descriptions from the publisher’s sites. When I download a cover image such as this one (http://www.audiobooksonline.com/media/Alex-Cross-Run-James-Patterson.jpg)
I always rename and re-size it before installing at our Web store. Would this process result in any publisher’s metadata in the image we use at our Web store and/or anything else Google would not like?
Is there an online utility that would allow me to see metadata in our images?

Should State names be abbreviated and/or fully spelled out in title tags, meta descriptions and body content? Does Google know that VT = Vermont?

I have a change, perhaps temporary, to my web store that I will be making. I am wondering if the code that I will comment out () gets spidered?

An SEO report, not by SEOmoz, says my top two competitors have robots.txt files that disallows spidering. I suspect that their robots.txt file doesn't disallow all spidering. How do I find out what is in their robots.txt files?