Using pick is not a matter of number of strings, it is rather a matter of personal preference or style of music you are playing.
With a 4-string bass, you can use both pick and fingers.
usually pick for better quality sound but thumb can be used
Yes he does in the video Dance Dance he does
Sometime before South of Heaven was released
A plectrum (not sure if I got the spelling right)
You can use a pick or hands to play fast, it just takes time and continual practice. One of the quickest and easiest ways to play fast is to practice with a pick.
Yes.
You can fingerpick using your....fingers or pick it using a plectrum/pick. Alternatively you can even pluck it or use a bow on something like a double bass.
usually pick for better quality sound but thumb can be used
It doesn't matter, but all the bass greats play without one. I personally don't, and you'll find that there is a great split in the bass-playing community - to pick or not to pick? Most don't, though.
Yes he does in the video Dance Dance he does
To use a pick on bass effectively, hold the pick between your thumb and index finger. Strike the strings with a downward motion, keeping a steady rhythm. Experiment with different angles and pressures to find the sound you like. Practice regularly to improve your technique and control.
Sometime before South of Heaven was released
A plectrum (not sure if I got the spelling right)
A good technique on bass is what feels right for you and sounds right for what you're playing. There's no hard and fast rules on whether to use a pick, how many fingers to pick with, how low to sling it etc; it's what works for you.
You can use a pick or hands to play fast, it just takes time and continual practice. One of the quickest and easiest ways to play fast is to practice with a pick.
bass pedal
There are several ways to play bass chords and notes on a guitar. You can use your fingers to pluck the strings individually, use a pick to strum the strings, or even use a combination of both techniques. Additionally, you can use techniques like hammer-ons, pull-offs, and slides to create different sounds and variations in your bass playing.