I see that a few of your original questions have not been answered yet. Here's what I know:

1) External keyboards. No you can't re-map the keys, and I think that is the Android OS rather than this particular device. Far as I know, no Android device can do the DEL key function. But certain external keys mimic the device's hardware keys or have special usages that come in handy:

ESC = Back button
F4 or END = Rotate Screen
Home = Home button (goes to homescreen, press-and-hold to show currently running apps)
F1 = Menu button
F9 = Volume up OR Page Up (depends on the app you're using)
F10 = Volume down OR Page Down
{Double-tap} Shift = CapsLock
Tab = Google search
F3 = Contacts

2) Position of USB ports. This is more preference I suppose, but I simply set it up differently. I either place the eInk side face down and have the LCD at an angle, or place it eInk side up and the LCD angled as though it was a laptop and the eInk is where a keyboard should be. Only time I would think to "tent" it is if I am laying on my left side on a bed and trying to read the eInk side, because it is not rotatable unless you format your PDF to be sideways.