Most of the complications in the session was because it was young children who arent used to these kinds of games. It was of course the youngest who got hit by the fumble and didn't understand it was just part of the game or that they would get something out of it that helps them out. I personally wouldn't change too much for a second edition, maybe look more at stretching it into long term play. The game is great and was so much fun narrating a bunch of kobolds bumbling around!
As for what we actually played through, I started them out in "The Pit" which is a large chamber in the Clutch where events and such are held. The event here was a tournament of capture the flag pitting them against some NPC kobolds. This was mostly to get them acclimated to the mechanics and to stress the importance of teamwork.
After they celebrated their victory we started the adventure in the base zine and set them on the path to finding the mushrooms. It was shortly into this part (leaving the clutch, but before making it to the ruins) when we had the fumble that spun the game out of control. For what it's worth, I was going to string it into Murkmire by saying the mushrooms had been picked and the trail led into a swamp nearby (where they were dealing with a similar sickness).
It was a fun change of pace from Uno and Sorry while it lasted, and in glad I caught that post on reddit all that time ago!