Yes, those are the two that I'm referring to.

I agree that if you don't tighten them up, then you can get sideways adjustment. However, why have a fully threaded screw/bolt (as opposed to one with a few mm unthreaded) with a spring washer, when it's not meant to be fully tightened?

Here's what the adjustment screw looks like with all its pieces laid out in order;
 

The long screw turns through the white plastic piece on the far left. That piece is secured in the trim ring. The other pieces allow it to turn and lock into place. Mine turns to adjust after replacing several of the internal pieces and screw.

The whole side to side "adjustment" is ridiculous...  might have been a government requirement?  Anyway, they got rid of it in the later bikes and just attached bulb to rim with clips.

Just center it as best you can and lock it down. 

I think they include the spring lock washers so if you don't have it completely tightened down, the nut will still stay on. However even if those screws are fairly tight, the light will still pivot, and with the fine thread of the adjustment screw it should be able to turn the headlight. I just saw the entire setup as unnecessary, which is why I removed it, rather than looking for a new screw. I kept the parts just in case.

In fact if I do right at night, it's much easier without that adjustment screw. I can stop and just using my fingers pivot the headlight to so it's pointing the direction I prefer.