"having things thrown at me from car windows (this has happened to every cyclist)"...I am genuinely shocked. I would not expect that from a third world banana republic, not a fact-of-life in the USA.
In LA it was common to give extra room to lane splitting motorcyclists, and they'd give you a wave to show their appreciation. Rarely do I ever experience the kind of courtesy afforded to motorcyclists I observed while living in LA as to bicyclists in the city I live now. I did have a gentleman with a bike rack on his car move over for me while stopped at a light to give me some room, but of course, he understood as a fellow cyclist.
My out-there suggestion is to force any able bodied citizen to ride a bicycle on the road prior to getting a drivers license so they at least know what it's like.
Or best of all, cities should model their bicycle infrastructure like Portland, as I can't even recall an incident between myself and a vehicle while living there because of how they designed and implemented bike lanes.
Although this is probably because I am courteous and acknowledge that my bike going 15 mph is essentially an obstacle to all of the cars which are going 45 mph.
"A lot of time" is probably not enough. I've spent enough time riding to have had at least 3 objects thrown at me, including a beer bottle, a wet wad of something, and some unknown object. On all three occasions these were juveniles having "fun", not someone angry about my cycling courtesy.
Oh and people yelling get off the road...
Lot of angry people live in this country; when they are driving cars it really comes out.
I rode shoulders and shared dangerous roads --no shoulder a bike could ride on alongside a 40/45mph road.
I never had things thrown at me. Now, I never intentionally tried pissing drivers off, that's for sure. Or maybe I was lucky, or those drivers were especially nice. Possibly as well, since I was only the odd bike, it wasn't irritating drivers.
On the other hand, I do recall a few other odd cyclists "advising me" to keep some D-cells with me in case I had to hurl one at a car. I never carried one.
That said, people thought it was peculiar that I would ride a bike and not own a car. Basically, I just could not afford one at that time.
In the Northern Virginia suburbs where I live, there aren't a lot of people on the sidewalks. When I do pass a pedestrian, I slow down and give them a wide berth so they aren't startled. Sometimes I'll even ride into the street to give them more room, especially if they're walking a dog. And then, I get back on the sidewalk where my life isn't in the hands of aggressive or distracted drivers.
Since sidewalks in many places are rarely used by actual pedestrians it'd probably be better, and cheaper, to install paved bike paths instead.