Well depends, really if you threaten anyone you can get into some kind of trouble, but government employees it depends, you could have a certain agency called on you or others just depends, but if i was you i wouldn't.
Added: Not enough information is given about the situation to give a meaningful answer. It dpends on the circumstances. If the threat was made to coerce the employee into, or out of, performing some part of his assigned duties, yes, it would be a VERY serious offense. If it was simply a neighbor-to-neighbor type of altercation/threat, simply BECAUSE of the person's job alone, probably not.
yes it's illegal to threaten anyone
Threats are typically not illegal, however, there are laws making it illegal to threaten leaders and government officials.
yes
it is only illegal if you didn't kill it in self defence
no, you can spy on a neighbor as long as you do not get in their yard or threaten them.
no
yes
Yes
It is illegal to not pay employees for mileage in MI if it was agree upon. Employers are responsible for meeting pay obligations to employees.
It is illegal to record employees without their knowledge. It is not illegal to place surveillance cameras in the work place but other covert means like bugging offices are illegal.
No, it's not legal to threaten someone with bodily harm anywhere in the United States. In most jurisdictions this would constitute 'criminal threat' or 'assault'.
That depends on the reason for the threat. If your supervisor threatens to fire you because you're not doing your job effectively, there's nothing illegal about that, but if they threaten to fire you in order to intimidate you into doing something illegal, for example, then the supervisor has committed a crime.