This is hilarious. Believe me that no investigator wants to talk to you longer than they have to. And no investigator just decides what they feel like asking in the moment. It sounds to me like you missed some required information on the form and are uninformed about the process as a whole.
As @backgdinvestigator said, new information seems to be trickling out, and when that happens the investigator has to figure out what details to obtain on the fly.
There are also standard questions that are asked in each section that go beyond what is required to be listed.
Whenever I quote someone a timeframe it’s after looking through their form already. A good investigator can review the form and have an idea of what the timing will be. But nine times out of ten when you sit down to the interview and suddenly all of this new information comes up that wasn’t properly listed, of course it will take longer.
On the other hand, i often get the communication to obtain additional information because the information provided by the Subject during the original submission was not valid or could not be verified.
If you feel strongly about the interview, do file a complaint. The agent/investigator gets the chance to reply to the complaint and could be investigated for misbehavior.
After all, i report to my supervisor when i have a difficult or controlling Subject. I have stories where I’ve had Subject’s demand my supervisor’s name and phone number during the interview, always at the beginning. Each time I have called my supervisor, explained i had a Subject wanting to talk to them, handed the Subject my phone, and stepped out (or attempted to step out). From my view, each of those were Subjects trying to control the interview through intimidation and threats.
We really don’t have time to mess with people. Even if the investigator over explains that they are used to working national security cases.
UWS - remember at the beginning of the interview when the investigator said you would be asked additional questions needed to help the agency determine your suitability? The questions you mention are in the 50+ page list of questions that they have to ask and report. Not all of the extra questions will apply to every applicant, but investigators do not get to randomly pick and choose which questions they want to ask and which ones to disregard. If any of your responses on the application trigger additional questions in a section and they don’t ask them, the case will be sent back for another interview to get the answers.
This entire process is subjective from start to finish. It’s naive to think that some investigators don’t take this process to the extreme and that others may minimize to the opposite end of the spectrum. If an investigator asked a subject to provide social security numbers of every immediate family member, most subject’s would do so willingly. We all know how inappropriate that is but Subjects and Sources are not familiar with this process and only exposed to it for brief periods of time every 5-10 years. If a Subject feels uncomfortable or squeeamish about what they are being asked they should not immediately cooperate. There is nothing wrong with stepping back and getting FSO or a supervisor involved.