1)
What is the significance of calling one who intends to harm "Ba'al Mezimos"?
1.
Rashi: One who plots evil schemes [to harm others], this harms him - people call him Ba'al Mezimos (counsel of Resha'im).
2.
Malbim: The verb Zamam refers to deep thoughts how to carry out a matter. In secular matters, it is usually for evil. Chashav is simple conjugation implies improper thoughts, e.g. Pigul in Kodesh (intent to eat it after the permitted time), or evil to his colleague. He is called Ba'al Mezimos for disgrace, i.e. his thoughts for evil are deep - "v'Ish Mezimos Yarshi'a" (12:2).
