No, I think that generally the police acts with appropriate tolerance and force at demonstrations and riots. Mistakes happen, last time was probably the mass arrest in Lucerne a couple months ago. But usually it are strategical errors that result in fewer arrests and more riots than necessary.
There was an unauthorised anti SVP demonstration in Berne that got out of control and has led to much soul-searching in the local authorities. They consider to only authorise stationary events and no more processions.
The authorities have not yet decided if the Antifa rally of next Saturday gets authorised or not. The case gets complicated by the fact that at the same time and place the dedication of the Bahnhof square will be celebrated. Also Antifa has made no formal application for approval, all contacts to the authorities are only informal. I don't know how good your German is but you can read about it
here and
here.
So please be aware that this could become an unauthorised rally, which always increases the risk that something can go wrong.
Also, I think you were gaping if you were in water cannon range at the WEF demonstration which, I suspect, wasn't authorised either? And please do not confuse private security agencies and police, their training and competences are different!