I've heard about the clicking noise at the top and bottom of the screen, I don't know if that's a big deal, but the looseness under the keyboard definitely isn't - they keyboard bezel is just a piece of plastic to keep dust out (well actually it helps hold the keys over the sensor pad too). Mine is loose there as well.

Over time my old Treo 650 would "loosen up" a bit, I'd just back off the screws a little and re-tighten them, and it was good as new. Getting a hard case for it solved the problem.