Intresting attitude Jason. Given your tastes in music, I wouldn;t have you down as somebody who'd want to do that, but I respect your desire to master your instrument so you can effortlessly play the music you wish too.
By shred, I think we're in a less clear posiiton than we were. Weedly metal guitar is certainly fast, but there are musicians in every genre now who can play some sick stuff.
The most importnat thing is to play everything very slowly and rythmically accurately with the minimum of required motion. Keep you fretting fingers as close to the strings as possible when not in use, so as to minimise the motion you reauire to fret notes.
If you get your rythmic accuracy really good and play efficiently in this way, speed will be a natural product. But it is most important to make sure you really learn how to do this well. Drill yourslef in doing this really slowly before accelerating it.
Here are two main schools of playing really fast. fret hand oriented and pick hand oriented.
Left hand playing is stuff like hammer ons and pull offs. All guitarists can do this. What makes it sound 'shreddy' is the use of manny hammer ons and pull offs. Practice playing ascending and descending scales using only one pick stroke per string. Here's an all purpose shred scale shape. Notice there are three ntoes on each sting. This makes it more regular for the picking hand, and reduces the demand on this hand.
An associated technique is tapping, by which I mean the soudning of any note by finger pressure alone.
For example, you could learn to play enture scales just using your fret hand, sounding the strigns with finger pressure alone. This will be very hard descending, as you will need to cordinate the
You'll probably want to mute the strings with your pick hand, by crossing your hands and muting the strings behind your fret hand.
When you have mastered this, add the use of the fingers of your right hand. This can make muting an issue. Here's an arpeggio shape a friend of mine rips through, although I simply can't get the hang of it. Every note is tapped - the high notes emp[loy the index or ring finger of the right hand in eddie van halen style - the only difference is that .
Now practice ideas that mix up the two techniques. Tapping and pulling off on one string is the classic Eddie thing.
Right hand techniques
Alternate picking is very right hand dependant, and essentially just means going down up down up for every single note. On one string this can be made to work very fast indeed, across the fret board it becoems very hard, so it is well suited for scalar passages, but much harder for arpeggios. However, alternate picking is really good for making you play with good time, as you can lock your accents with the rest of the rythm section. So you should practice everything alternate picking, even though there may be limits to how fast you can make it work.
This is the use of a single pick stroke across many strings to sound several notes. Practice raking the muted strings with your pick very slowly, and make sure each 'pop' is rythmic. You will find your pick may bounce slightly when you do this.
Now practice these shapes which have a single note a string:
You can change direction from an up stroke to a down stroke very rapidly by doing an even number of strokes on the top string of the pattern:
you will also sound like woody woodpecker.
This is a combination of alternate picking on one string mixed with sweep picking for moving across strings. In most real world musical situations, it is this picking technique which offers the best allround mechanical efficiency and therefore the greatest speed, but there is a cost in terms of rythmic accuracy.
In most case, it is best to mix and match among ligado, tapping, sweeping, alternate and sweep picking for the bets execution of musical phrases. George Benson uses alternate, economy and sweep picking along with other picking patterns for extremely agile but highly musical results. If you sweep pick all the time, for example, you will sound like Frank Gambale, who for me is the most unmusical guitarists I've heard. On the other hand Allan Holdsworth only uses fret hand tapping (no ligado!) and he sounds very msucial, so there are exceptions.
This is a bit of a quick overview - I'm sure others can elaborate on these techniques and how to do them.
NB: check with a *good* teacher to ensure you are playing with a healthy and effeicent tehcnique. Fret hand stretches can be dangerous if you have a bent wrist.
Good luck! I pity your neighbours :-)