to the OP the song sounds like it's in C Major and I hear a G somewhere and Em at the end the song is all open chords
as far as learning the guitar, play what you like and alot of folks think shit is the guitar olympics these days
learn barre chords and you can play about anything
as far as that ear shit, I dunno as long as you can hear E you fine
guitar is not about showing out, just like swimming alot of black folks can't play guitar, they either play the bass or drums
some of the greatest songs are simple and have great rhythm and often mistakes or sloppy playing etc, far from perfect sounding, however with all this digital processing and mixing these days music has suffered from being perfect
for example the problem with Prince is he has improved on all his instruments ( he is a far more complete guitar player then he once was) and in the studio he puts out perfect albums now, where as in his hey days his albums had plenty of playing mistakes, mixing mistakes which now his mistakes etc are only captured at his live shows
take for example
this Eddie Hazel Maggot Brain
http://www.youtube.com/watch?v=dh3bleXWaCk
Sound's good, but it's really simple
solo in E minor, you could play this solo in two positions
backed by some appregiated chords that repeat
some heart, some tape echo and some fuzz