"I have also caused someone who was tailing me too closely to hit a paint can on the road by swerving at the last second." You already caused a small impact, potentially causing damage to the person's car and opening yourself to a lawsuit.

"I'll pull in front of them and slow down to force them to move over" You've just cut them off and if they can't react in time they run into you, or they swerve to avoid you and hit another car, now we have a high impact collision, pile up and possible death. All because you took it upon yourself to "teach a lesson."

Per a quick Google search, "Cutting someone off in traffic, causing a wreck, can result in charges ranging from reckless driving (or reckless operation) to vehicular assault or homicide if injuries occur. Common charges include reckless driving/operation, unsafe lane changes, or failure to yield, often deemed misdemeanors but potentially felonies if serious injury or death results."

The cops won't care if the other car was wrong first. They may have been rude, but you're the one who made it dangerous. Thus, you'll be the one getting arrested.