don't want to? Not really how this works, there are rules and regulations, arbitrarily "not wanting" to grant an immigration benefit is not really a thing with USCIS
I mean obviously the fact that they were sent to secondary where they specifically stated they wouldn't adjust & THEN applied for adjustment, anyway, is a rather relevant point of fact & not applicable to OP's situation AT ALL....
It's USCIS' policy NOT to deny an adjustment of an IR of a USC based solely on intent so no need to prove intent. It was decided at POE that he didn't have intent, otherwise he wouldn't have been allowed entry.
He was being serious and the threats are a tactic to draw out dishonest people. You're not dishonest so you're fine.
Don't read anything into how he talked to you. It was an act.
8 months' overstay is a 3-year ban. But the ban being over doesn't mean a guarantee of getting a visa. Indeed she may never receive another non-immigrant visa with her history.
No, the court can only force a decision. The court doesn't approve or deny. The court issues an order to the DoS to render a decision. The DoS then obeys. The decision can be denial, it's up to DoS.
This is routine, I was also told this at my N-400 (not combo) interview. Often they have to get a supervisor to check everything before they can approve.