What Type of adhisive are you using to adhere the new lens to the lcd? Make sure you are not damaging the cables when you are removing the outter lens i have ran into that problem before to much movement in the lcd cable will cause lines.
if the screen is "ghost touching" Meaning just randomly touching places and acting wierd. 1 of 2 problems. 1. Bad connection Clean ribbon cable with alcohol. Reconnect digitizer flex. Reset the device 2. If that doesn't fix it than more than likely you have bad part.