#1
I'm going to start trying to practice about 3-4 hours a day, and I need some help.

What are some good exercises that will help me with speed and accuracy (both fretting and picking)?

I also want to improve on pinch and artificial harmonics.

I'm not trying to learn how to "shred." I just want to play better. I mainly play Thrash metal.

I know there are good video lessons on Youtube, but I'm one of the 20 people who still have dial-up but go ahead and post a link to one if you want.

Also, what are some good DVDs or programs for improving?
#2
Speed and accuracy are just muscle memory techniques. Once you learn what you need to play, you just play faster and it'll be accurate (hopefully)
Live as a man. Die as a man. Become a man.

That's the proof of your incompetence, right there.
You lack the qualifications to exercise free will.
#3
For exercises do 1-2-3-4 on every string then 2-3-4-5 on every string and so on through the whole neck. I have heard that john petrucci's instructional video "Rock Discipline" is good.
#4
Try and find Steve Vai's ten hour workout somewhere (You don't have to spend ten hours on it though!)

Practice SLOWLY with a metronome to start with, and I guarantee your accuracy will improve hugely.