To answer your first question, there are probably more PDAs in use without screen protectors than with them, and I've met quite a few people without them who say their screens have never been damaged. I had a Treo 600 for about 2 years, kept it in my jeans pocket, dropped a few times, used the stylus like hell, went camping in the dusty woods, took it snowboarding, not a single scratch. Then dropped it one day and cracked the screen, which a protector would not have helped.

For some reason I decided to get a protector for my 6700 though, and I can't say enough about the pocketpctechs.com protectors. Kinda tricky to get one but invisible once you do.