I've never used a screen protector on any iPad and have had no screen scratches. But I do use a sleeve case when it is in a bag.
So far I am loving the air. Easy thumb typing in portrait and two handed touch typing in landscape. Easy one handed holding in portrait or landscape as well, and I dint feel the need to rest it on something.
Not as easy as the mini of course, but I don't want to give up the input accuracy of the larger display.
Thank you! I just needed that little bit of wisdom from an experienced user.