I can't say with certainty what the bezel does, but my hunch is it has to hold the glass in some way, as I've tried all combination of tape around the very edges of the screen, and they all affect touch response to one degree or another. If the double sided tape looses its adhesion, the bezel has to provide some support or it glass would shift. I have just laid the touchscreen on the counter and tested it, and my second unit responses very well to single touches, but like ASIHome I have difficulty doing a tap and drag.
Because the touchscreen gods did not smile on me with either a unit with a bezel or one who's foam is still tacky, I'm going to try to incorporate glass supports in my custom frame. I am thinking of routing a "ledge" into the bottom of the frame that the glass can set on.
--Jamie