um...how many screens are you planning to have in your car?
1. You have to understand TV output is a very poor quality for text...If you're planning to read stuff on that screen...good luck guessing the letters.
2. Yes you can do your setup...If I understand correctly. You want LCD monitor with Touchscreen, output from TV-out + another monitor plugs in the VGA port.
The touchscreen kit is almost like a mouse itself. When you calibrate it, it will function even with the LCD off.