Go to Window > Animation. Window is menu item in application menu at top of screen (File, Edit...Window). Click Window to expand menu then click Animation.
Yes, for many reasons. But the main reason is Photoshop CS5's Content Aware feature. If you select a area in your photo and click the delete button on your keyboard it will fill in the background...
Photo shop CS5 can be downloaded from the Adobe website (See links below) which will let you use it for thirty days as a trial version before you have to pay for it.
You can just look at the price in Adobe.com. Or you can get a cracked version for free, I'm not allowed to give a link, but you can google it and you'll find many good downloads.