Maybe a short trimmed beard is ok, but even then I question their ability to discern small differences with one test. Your beard sticks down and is hitting clean air. Really doubt that is good.
All those helmets sound promising.
I'm thinking stuff on the rear should be closer to your butt.

Sounds like you should see some marginal gains. You could also experiment with going lower in front.

There's a lot of evidence that stuff on the front that hits clean air is of primary importance. If it was me, I'd swap your brake levers for something with less frontal area, and just put a line of skateboard tape on top of the hand grips (no bar tape).

What tires and tubes are you running?