I wouldn't say its more susceptible to scratches than any other phone. The screen is huge, but the plastic quality is good.
I tried screen protectors as well. I didn't like how they affected the display so I'm protection free. I do, however, like to put two or three layers of wax on mine. Been doing this on my phones for years.
Can't say that the default case caused any scratches, but that vinyl is pretty crappy. I put mine in the case with the screen towards the hip, speaker out. The short side can be pushed into the screen the other way.
If it gets scratched, use some polishing compound. I like the 3M stuff.
http://www.superiorcarcare.net/3mplaspol.html
I also suggest the ebay magnetic flip case. Had one for a few days and its awesome.
http://cgi.ebay.com/ws/eBayISAPI.dll...sPageName=WDVW.