The inability of sims in TS4 to remain sit on a chair for the whole length of a meal, study session, book reading etc... makes me want to turn off sims autonomy quite often, I struggle with that also when playing smaller households...
As for the potions instead, I tried only once with a sim running a potions shop (so he had to produce at least once each one of the available potions to have something to sell), but it really took ages to collect all the ingredients and learn all the recipes... But at least now I have a place where all the sims in that save can easily purchase any potion XD
Anyway, you seem to manage your (objectively) hard to handle saving very well, also the duel tournament sounds like a very funny idea for this kind of setting! I'm also a bit worried by Rita Skeeter appearance, she is definitively the kind of character who can make trouble in any storyline...
