Yep my krausen just fell after 18 days, don't worry about it go do something else and forget you even have that beer sitting there for a few more weeks
Not necessarily, my first one (the one I am on now) "bubbled" for almost 3 weeks. That's not to say it was fermenting the whole time although I suppose it could be. It can either be co2 coming of the yeast cake or dissolved co2 in the beer itself. You should never judge fermentation from airlock...
Yea mine was they same way as Yoopers, I spent like 10 minutes thinking that I had the wrong lid and out of frustration I slammed a lot of my weight on it when I was trying to put it on and what do you know it snapped right on. Can be a pain to get off as well because of the tight fit.