Yes. The IRS is especially known for garnishing your pay and seizing your property. Other federal agencies can also do these things with a valid reason.
No, only the federal government can garnish your wages.
Unfortunately, there is not a universal answer to this question. Each state has its own laws governing an employer's ability to garnish an employee's paycheck due to money missing. Some states allow it, some states don't. So, it depends on the state in which you live. The federal government does not have a law that either allows or prohibits employers from deducting missing money from an employee's paycheck.
The IRS can garnish your wages if you owe the government back taxes or defaulted on your student loans. They can take as much as it takes to pay off the debt.
The fewer allowances an employee declares, the more money the federal government will withhold from a paycheck.
The 16th
FOREVER
Yes. If you are presented with a court order to garnish your employee's paycheck you must obey it. Disobeying a court order could place you in contempt of court.
Yes it is.
tax
tax
WithholdING taxes
withholding tax.