Imagine if the FBI did any investigating prior to avoid the easy and obvious authoritarian parallels while questioning a free citizen working for an elected representative.

I want the FBI to do their job; I just don't want them to look like and/or be the bad guys. In this situation, they smell like the bad guys.

Why should FBI be interrogating people without their lawyers present, when they have no evidence of a crime? The FBI should not be deploitng Gestapo/Stasi denunciation tactics on anyone.

Talking about tear gas in the privacy of one's home is not a crime. If that appliance repairman was the "informant", he should be in jail for wiretapping.

Nope, if you are stupid enough to talk about important confidential topics in front of rando strangers you have no expectation of privacy. These are the types of people Chinese spies target and harvest information from, if anything this staffer should be let go for mishandling information.

> When she told them about the proposed legislation, they insisted on knowing what it would say, whether it would be formally introduced, and when.

Is that really necessary?

I would imagine that those questions would be easily answerable if true, similar to how a border guard might ask seemingly random questions in that context but a series of 'uh, uh' answers might indicate something else. Sometimes investigators ask questions just to keep the target talking and build a report. Those questions are reasonable to expect a public figure politician and their staff to answer.