Just read through the playthough, was a fantastic read! Thank you so much for the coverage!
As for the rules question, if you fail a challenge (assuming you’ve already tried a different approach as outlined in failing tests section, which is optional), you draw a new river card. This rule is in ‘The Game’ section - once a scene is complete, success or fail, you draw a new river card. The FIND ANOTHER WAY consequence is referring to the river itself, and causes the river to fork.
Hope that helps!