C2 headlights

So what does total removal of that do?

In normal use, nothing. The regular beam pattern, shone on a wall, will have a pronounced upwards 'kick' to the left on RHD cars and to the right on LHD cars for the reasons Tony described. Removing the little shutter from the light will just remove the facility to mask this kick and flatten the beam.
 
The tagged section is usually out of the way, but only needed when going abroad so rarely gets used, if ever, as most don't even know it exists, I want to see if I can modify it to make the lamps legal on either side of the road
I only know about it because I took a light a part and examined everything. That was one of the pieces that made me say WTF?