Questions about my new iPod Touch

After few weeks of drooling, I finally got my iPod touch today! Its a week 44 but I have yet to open it. I wanted to ask a few questions first:
1) How do you test the screen for negative black effects, stuck pixels or the scattered green artifacts effect that I have heard about?
2) Anything else I should check other than the screen?
3) Can anyone recommend a good case? The new iSkin ones look good, but would they take a long time to ship since it's new?
4) What are the benefits of jailbreaking? I'm not going to use the calendar so it doesn't really matter to me whether I can edit it or not. The only app that sounds useful would be notes, yet I still don't know how much I'm going to use it. I have a nano and all I used it for was to listen to music. I don't even use the photo feature much and almost never play games.
Thanks in advance!