#2
Learn the intervals. Learn scale formulas. learn notes on fretboard, learn some chord theory, and just play.

Using your ears is good, but it depends on the person.
#3
this is basicly what i want to do as well. what im doing to learn is i have a few books on scales, arpegios (spelling? =\ ), and chords. i also had a teacher but he was always "sick" and the subs were horrible so i stopped with him and im looking for another teacher currently. basicly im just messing around with different arpegios, chord progressions and scales (lots of pentatonic scales because those make for easy improvised solos).

basicly all i have learned so far is that if you just play the notes along the scale/arpegio or w/e then it gets very boring so you need to use aproaches to the note as well such as a fret below the note then the actual note or two frets below to one fret, to the note etc. (hope that makes sense)

hope i helped.