The big thing I want is for me to 'drive' and them to watch and then give me verbal feedback (or type in their password), without me having to drive an hour. :)
Some areas I need to investigate:
I need to look into security concerns with an open hole in the firewall for VNC, and the the security of VNC itself.
I'm excited about the idea that you can turn the HDMI on and off from the PI, which should make it such that I can trigger their TV to turn on and switch to the PI. I need to look into whether or not I can change it back. Mabye an IR transmitter or CEC.
I should also look into gathering feedback from the aging party through their remote using CEC. It may mitigate the need for a mouse or keyboard.
I need to look into camera as well.
Invariably, they're going to point at the screen. I have no idea how to deal with this yet...