Not noticed it being easier to scratch for me. I use a small silk cloth to wipe it over and a bit of breath (as if I were cleaning glasses or lenses) not noticed any scratches on my screen. I've kept it in a case but also dragged it around with me a fair bit so would expect it to have acquired a scratch if it was going to.
I also have a dead pixel sized scratch on my rMBP. Just found it today. Middle of my screen and anyoning. I'm sure I will get used to it but after paying $3000USD for it just 3.5 months ago has got me fustrated. I got this screen because I am photographer and wanted that extra resolution. This screen does seem more sensitive than others I have had. My previous laptops seem like they went at least a year without a nick in the screen.
As for the AppleCare portion of the question, I am not sure. Would love to know.