Hmmm... Am I misunderstanding what you mean by bezelless? There seem to any number of devices with their touch screens flush with the edge of the device. Iphone? Ipod Touch? The Nokia Tube? I'll freely admit to not owning any of them, but I haven't heard reports of rampant screen breakage either.
And yes, as you mentioned, the primary advantage of an eInk based keyboard relative to the onscreen keyboard, would lie in increased display/interaction space and it's capacity to be reconfigured on the fly depending on application. I guess the only advantage it would hold over actually hardware keys would be the reconfigurability and the possibility of using it as a display (ebook) in addition to using it as a input. I mean conceivably you could get the same by including a second display, either LCD or OLED or what ever, but I figured eInk was cheaper, better energy efficiency since it's bistable (read: battery life).