My 2 cents. I don`t plug into RockSmith anymore, like ever. I`d like to think I`ve become a bit more advanced (ear training, rythm), because I practice in pianomarvel, bass, guitar, jazz, etc and I`ll tell you this one thing-Play through a separate amp and listen for yourself. Day after day and week after week you`ll start noticing things, fix them and play better and better. Your timing and technique will improve exponentially. But be prepared to give more effort too.
Ditch the fucking cable, get an amp, play with both your guitar AND the band really loud, count the rythm, be in the pocket, enjoy those sweet guitar gains.
P.S. Never, ever be afraid to go even at 50% speed, until you can play that cleanly. If you play the song 3-5 times at 70%, magic will start to happen.