rush, i laughed out loud at your comments about holding the windscreen, the books and the internet on the bike. way too funny of a picture in my mind.
I will sometimes do the one hand hold, no not that one,

while on the bike, and as mentioned sometimes my shoulder stiffens a bit so I relax my shoulder with a hand on the hip. But never in traffic, just when I can be sure to get both my hands back on the bar in an emergency swerve or braking. Plus, btw, i do have a cupholder on mine and do have a soda in it at times to drink while riding. Maybe I shouldput an empty whiskey bottle in it to really rattle em up out there when they see that!