Thanks for starting this thread @fulfillthedream
I've gone skating with a ton of different people from all over the world. Needless to say along the way you start to notice what trends can cause interactions with the general public to go well or bad.
On the negative side of things skaters who assume the general public are in tune with what direction or what obstacles they are skating need a reality check. Let's face it, people are not always aware of their surroundings and having a skateboarder scream at them to move doesn't help much. It's much better to approach the person calmly and explain what your intentions are and how you don't want to run into them. Of course this is all situational, if you have the time to handle things like this, go for it. If it's an emergency and you are going mach 5 and someone jumps in your way, that's different.
Traffic control: There is a reason why the police wear brightly covered clothes and have whistles to make loud noises to control vehicles. Getting pissed at the driver of a car for not slamming on the brakes because you smashed unexpectedly into traffic is the wrong approach.
Skating fast through pedestrian zones... slow your roll, you don't have to impress people because you can dodge other humans and make them feel uncomfortable.
In general the reaction towards getting the boot. Yea, it's a bummer but that security guard will put their job at risk if they don't at least make an attempt to inform you of the property rules. Of course some security guards overstep their boundaries and take their jobs too seriously but there are ways to diffuse the situation. Kill em with kindness. Talking shit on them because they have taken a shitty job to put food on the table / pay rent, come on now.