The "too short to count" rule makes more sense than people want to admit, because a full discussion slot costs everyone the same thing no matter how long the book is. If you get one slot a month, you have maybe 10 to 12 slots a year, and blowing one on a book people read in a single sitting means somebody else's 400 page pick gets pushed to next year or dropped. The 600 page book that fell flat is a bad example too, because that is a problem with the pick, not the page count. Short books also make it easy to show up having skimmed, and then the talk turns into a 20 minute chat instead of a real meeting. Most clubs that stay alive for years run on some kind of limit like this, even if nobody says it out loud.

That 11 day shoot explains everything about why Part 2 feels so loose and fun, they had no time to second guess any of the dumb stuff and just threw it all in. The chainsaw bit is a perfect example, a bigger budget would have ruined that scene because someone would have tried to make it look real. You're not alone on this, the sequel knows it's trash and leans all the way in, which is why it holds up better on a rewatch.