When I was there, the protests were peaceful, but you could certainly feel a tension building up, with the crowds gathering metal poles and bricks. I spoke to the police a few times and they were nice and friendly, but were doing their job. There is absolutely zero question that almost the entire HK population opposes the extradition bill which sparked this whole mess. Unfortunately, there's little that can be done… "one country two system" hasn't been abided to by China for a long time, and there's nothing the population or the Brits can do about it.
(My perspective is that of a foreigner who recently moved here, not a life-long hongkonger. Feel free to ask me anything.)