"Weird. My wizard didn't get to choose a legendary trait with Fountain of Legend quest, but my monarch did Fisherman's Challenge with no problem, gaining the Natural Leader LT afterwards."
Is it possible you answered the riddle wrong at the end of the Fountain quest? At the very end you have to answer a riddle, and the right answer is always the answer that has to do with your Fatal Flaw. So for Drunkard it's Wine, Licentious is Love, etc.
The 'Industrious' Legendary Trait lets you give 100 Simoles to any other Sim, and unlike Merchant's Bribe can be performed over and over again. If you can get this trait on a Hero who can make lots of cash quick, they make a great Monarch for the Wealthy Populace ambition. I had an Industrious Bard-arch who just played music and gave all the money away, like a medieval Bono or something. Anyway it made that ambition easier.
'Meat Quest IV' for the Merchant unlocks three recipes kingdom-wide that give +50 focus boost for 6hrs with relatively cheap ingredients (one is apple + barley). Just choose to give the meat to the village rather than sell it to the Monarch when prompted.