I haven't experienced that particular problem, but an easier way to fix the few bugs I've come across is to create a new project and then import the entire old project into it. No copy/pasting needed. Not sure whether or not that would work for your flicker issue, but it might be worth a try.
I loved Interstellar. I don't want to comment on most of your points, but I agree with points 1, 3 & 7.
#1: I think the first act seems awkwardly paced because it was cut for time. I saw it in 70mm IMAX last Tuesday (also in a sold-out theater), and they explained that the entire film was trimmed as much as possible because they couldn't fit another foot of film on the plates for projection (which is always why the credits are so brief).
#3: I also couldn't hear a lot of the dialog, but I thought it might have been where I was sitting (2nd row center). I heard laughter around me during those scenes, so I assumed the mix was imperfect from my location. Perhaps that wasn't the case.
#7: I have to agree with you here. It did look incredible, but not by as much of a margin over digital projection as I had hoped. I'm going to back to see it this weekend (in a 4K IMAX theater), and I'll solidify my opinion then. But like you, I also disagree with Tarantino – as much as I'd like to agree with him.