The least worst is that we don't win the league or the CL. We can't win the league every season and as we have never won the CL, whilst disappointing, it's not the end of the world.
We don't retain the League Cup or win the FA Cup. The LC probably won't be thing for top PL clubs soon and we generally don't win the FA Cup so hardly a disaster.
We don't finish in the top four. From a personal point of view I don't give a rats arse about the CL but obviously the club do. It would be a big hit to our finances and I suspect that Pep might not see out the last year of his contract. As he isn't staying forever then it means we get to greet our next manager a bit sooner.
I suppose the point of this thread is that life goes on and so does our club. There will be ups and downs and maybe we are entering a down period. I'm in my 60th year of watching City and even when I've been pissed off I still can't help being City daft.