Good questions Oosh,
1. The physical dimensions of the screen (PCB) is 98mmx60mmx~15mm. THe actual LCD part is smaller.
2. To remotely mount the LCD is not that hard, as long as you know what you are doing. Im happy to sell a display with the LCD and case seperate, so you can mount as you wish. Its 12 wires between the LCD and PCB, so a decent ribbon cable should do the trick. I would recommend you letting me know if you want to remote mount the LCD, that way i wont solder it on in the first place (and create extra work for you).
2a. Won't affect operation at all, just shield the ribbon cable to reduce noise.
3. A super bright VFD or LED module could be used for HUD. LCD will never be bright enough to be used as a HUD.
4. Not possible without re-programming the device, which im happy to do (at a small cost). Just tell me how much you need it tweaked by, and i'll write the code to do it.
Impakt