You can choose to believe me or not but I put this build together in 5 minutes. I just revised some of the things you pointed out. The name "BOOM HEADSHOT Lux" is just something I came up with on the spot, not to describe the build. Thanks for pointing those things out though.

Just a few things, I think you are on the right track.

1. Why Rylai's Crystal Scepter? Light Binding already Snares, Prismatic Barrier wont trigger the slow effect, Lucent Singularity already slows, and Finales Funkeln is usually used at such a range that a slow wont be very useful.

2. Which boots do you use? If you don't use any i'd be interested in hearing your thoughts on why.

3. I agree with the Magic Pen Marks, but I feel you would be better suited with AP per lvl Glyphs. Unless you want to go all flat AP for an early kill "not advised", but only stacking flat AP blues seems a waste to me.

4. Same for the Seals, I would rather see Mana Regen Yellows than flat mana. I think if you try these out you will find you have much more lane longevity.

5. Which Quintessences do you use?

I'm sorry to say that with the Title of "Boom Headshot Lux" I expected to see more High AP items, instead of AP+Health items. I myself play a high AP Lux and greatly enjoy it. I am going to give you a down vote for now, I believe in being honest so there it is. If you add a little more depth and explanation I will be more than happy to change my vote in the future.