I completely agree. Two other big causes of problems that I never see brought up are. Clear rules about what is allowed/causes a response. You routinely hear protesters complain we did nothing and the police started firing tear gas or moving in on the crowd. What they don't know is if the fence between the two sides gets pushed or moved police consider that aggression and respond. That's just an example, but when both sides understand the rules it makes things safer
another thing common language to communicate through the two sides. Police are abusive when clearing the streets, they push and club people, they spray them when they turn around and stop moving. A protester isn't going to know what is happening and it is human nature to turn around and ask, which police respond to by hitting them. It is a bit of insanity.