Thanks for the words of encouragement :)
On the "pi" concept, the solutions here are either the nexys4 board or the tiny trenz board with the same FPGA. It will need a daughter board for the VGA out etc, which someone will need to design. Better to wait until we know the price for the m65 though, as it will be such a nicer experience than a bare FPGA board.
For the megaphone, it will have at least VGA out, so you could put an adapter on for HDMI. You will also have the on screen keyboard, but no plans for USB keyboard. But again someone could make an adapter that would go on the joystick port to talk to a USB keyboard.