I replaced all of my fairing screws with hex head screws. When installing, just start each screw a few threads so you can move the fairing to start the next screw easily. It's not rocket science!!!!
+1 on the magnetic tip. I use a ratcheting screw driver type w/mag in the shaft. +1 again on getting all screws started first before tightening them all. That is always true with almost any multiple screw or bolt on part.
I just have a set of torx drivers. (Think screwdriver with Torx heads.) It gets in there as easy as can be. Leaving fasteners off of a Milwaukee Vibrator isn't a good idea.
He probably has broken vertical brackets inside the fairing and the vibration causes them to loosen and fall out. That happened to me before I fixed my broken brackets.
I was missing one of those screws and the fairing rattled. Got a replacement screw and the rattle was gone. I'd say put the screws in. It is no effort to get the fairing buttoned up tight.
I have found starting the bottom two first is easiest after starting the 3 windshield screws. I've had mine off at least a dozen times in two years with no issues. So what really burned me is when I had them (dealer) install my new brake line (braided stainless) because I have ABS, a couple of days later one of the lower screws is missing and the other is cross threaded. I can't understand if this is what you do for a living how you can not know you are cross threading a screw. You can tell so easy if it's being properly threaded just by the feel of it. Just one of the reason I like to do my own work besides the money I save and knowledge I gain.
The screws are there for a reason, I wouldn't go without having all hardware installed.