love your angle finding device Adam, I presume you have to get the guitar body level first ?
Maybe the neck still needs to be played in a bit more and I suspect a tweak of the truss rod should lessen the string buzzing.
Also changing gauge strings can change the bow of the neck with heavier strings putting more tension on the neck. see how you go with the heavier gauge strings. I also suspect your nut may still be a little too high. You may need to widen the nut slots a bit for heavier gauge strings or they may sit too high