I remember what a relief it was to be done with the medical and interview, I got a refusal for my medical as well.
Glad that everything went great, the officers handling the immigrants visas really are professional and quite friendly at the embassy in Sthlm.
I have to say though, one officer was very harsh and rude to a family next to me, and as you said, you can hear EVERYTHING that's being said at the windows next to you. They were flat out denied tourist visas and the officer was not nice about it, lol.
And yes, you go in the immigrant line when you're there for a K-1 visa, there's usually just 2 or 3 people in that line. Not a huge deal I bet, but they have signs showing which line to go in (one for K-1, CR/IR-1, citizens etc - and another line for all temporary visas like J/F/O etc, the latter is normally super long but since the embassies aren't processing J or F visas now, it was probably a lot shorter than normal).