As a cyclist, I get to decide if I'm a pedestrian or a vehicle. I can pop on/off my bike at will. I can ride on the road, then ride up a ramp onto the sidewalk for 4 blocks, then back onto the road. Different rules and expectations hold depending on where I am, but I don't understand this criticism. At least where I live (Seattle), riding on the sidewalk is perfectly legal.
I don't always signal, because bicycles have this major flaw that your breaking/steering tools work best when you have both hands on the handlebars. So if something hinky is happening ahead, I may need my hands to slow down instead of signalling.
I try not to yell angrily when people do dangerous things around me but I do often need to yell loudly, maybe repeatedly, in order to stop a car that doesn't understand that my bike is front of them, and they can't proceed without killing me. But you should understand that the stakes are much higher for me a cyclist than for the driver of a car. They might hit me and that would suck for them. I might die or need months of physical therapy. So be patient with cyclists who appear to have unleashed random anger at you (you-the-driver), they are under more stress from the interaction.
Also, the lawless cyclist trope, while often true, is often a case of the lawlessness you are unfamiliar with. I bike-commute most days, and EVERY SINGLE DAY I see cars: speed, run red lights, yield-instead-of-stop at stop signs, turn without signalling, wander into the bike lane, park or stop in the bike lane, drive without lights (at night), or with one light out. Also, it may not be illegal (but sometimes is!), but when I'm in a 'sharrow' lane, I will often get aggressively passed by people who can't be bothered to look 200 ft ahead to the red light, or who pass over a double-yellow in order to get ahead of me, then turn left/right 5 seconds later. But because we're all used to those kinds of infractions (and because they are partially 'our' infractions as drivers) we don't notice them. Because there are so few cyclists, and they aren't 'our' infractions, it's easier to notice their driving transgressions.
Anyway, super long rant. Not claiming all cyclists are angels, but as someone who is literally making it easier for the cars on the road BY NOT DRIVING TO WORK, I wish I got a little respect instead of the barely tolerated contempt I get a lot of. yada yada yada, plenty of good drivers out there as well.