|The Shifty Mongoose|
First off, it's great to hear that you, Rudy, re-examined your initial decision, listened to criticism, and came to a better decision with the help of passersby on the internet! It can be done!
Secondly, whether I'm in the Player or GM's seat, I always go over ruling decisions with everyone in order to hopefully defuse difficult issues. If a corner case comes up, I'll bring/ask for the confusing thing in question, and try to stay open to compromise unless someone's actually trying to get away with something they shouldn't.
As for the Masterpiece itself, I did get worried on my first reading of it; then, on my second reading, it struck me as a sort of magically-empowered Dunning-Kruger Effect, whereby your wilful ignorance and lack of self-awareness makes you certain that you know more than people who know that a given subject's more complex than it sounds. While you couldn't really tell what kind of plant that is, how much that rug is worth, or which Empyrial Lord is the favourite of this group, you can make a wild guess with +4. If nobody corrects you, or even knows if your guess is wrong, your dance can remove the penalty for telling an unlikely lie; how would they know if you're wrong?
"Praise be the Living God!"