Hahaha yea for a moment, I was wondering how this was related to Wolfenstein. 
Glad to hear that you got it working with the Keyboard control setup. As for the weapon aim location, if you open up the BP_Weapon_Parent blueprint, you can find an interface function called RetrieveMuzzleLocation which is used by the targeting component to determine where the targeting starts from irrespective of the owning actor. By default, I just put in a placeholder arrow component for the muzzle, but you can replace it with the muzzle location of your weapon.
And also make sure to attach the LaserTargeting component in the weapon blueprint to your actual weapon muzzle point instead of the arrow component. That should automatically make sure that the laser fires in the direction of the weapon aiming.
I guess that should make the laser align with your weapon. Let me know if you run into any issues.