If I understand correctly, the USB link is just to transfer still photos. On most normal camcorders, you usually use the firewire (IEEE1394) link to transfer video footage from the camcorder to the computer, but since yours has the dvd, you should just be able to play that on a dvd player.
Yes, you would need to make sure the DVD's are being finalized to be able to play them in a normal dvd player. You might check and see if anyone else has this camera and can give you suggestions, or is all else fails, go back and read the manual.