Don't worry about them, every noobie get flamed. I don't understand why, probably because they were flamed as noobies?
If you buy a complete VGA unit you won't need a controller. Check out
www.digitalww.com for some ideas on LCDs. VGA is the "standard" for pc computers, it's the 15 pin d-sub cable.
The quality of sound from a car-puter is generally the same as from your desktop. You probably already knew that it's mostly based on bitrates of your digital music. Low bit rate = crappy sound.
Hard wireing the connections shouldn't be too hard as long as you are decent with a soldering iron but why would you want to? My motherboard came with the IDE ribbon cables, powe supply with power cables etc. You don't need to hard wire any of your connections. Another reason you might consider not doing that is the possibility of breaking something. Also, what if your hard drive crashes? Do you want to try to hard wire another hard drive? Probably not. Trust me, you don't want to hard wire anything.