i think as long as the laptop pieces are held down well and you have adequate cooling, it should be fine.
as far as the sound card, you can go to device manager and find out which card you have and find the specs on the web. the ultimate test will be listening to it in your car to see if the sound is acceptable to you. if it is, you're good to go. if not, pick up a usb sound card. today i just saw a SoundBlaster usb sound card for $40. you can probably find them much cheaper on ebay or elsewhere on the web.
not sure about the apple dvd drives, sorry.
as far as the screen settings, i just use the "auto" feature on my lilliput.