I don't know if the police actually act on one person's word that a driver was threatening. However, if they log the call (as I assume they do) and if there is a pattern and if Something Really Bad happens, your report could be used as some sort of evidence. Cold comfort, I know, but better than nothing.
What I'm saying is that I'm inclined to report in the hopes that it will be used. And who knows, the cop just might be looking for an excuse to go talk to the guy.
As for the negligent ones, um, watch out? I can't think of a better way to deal with them.
Give big space to the festive dog that make sport in the roadway. Avoid entanglement with your wheel spoke.
(Sign in Japan)
1978 Raleigh Gran Prix
2003 EZ Sport AX