Hey thanks! You might want to try the Hendrix approach where you play major pentatonic scales over the I VI V I chord changes. You shift from G Maj pentatonic, to C Maj pentatonic, etc. This approach sounds very melodic and has such a cool sound.
On your second question you should check out the lesson techniques I showed in the Folk Guitar Legends lesson on Jim Croce style, even though this lesson is shown on the acoustic guitar you can apply the interval/harmony techniques on electric as well! Check it out:
Jim Croce Lesson