Ooh what if you added potions?? Sims could create them like herbal remedies! Maybe in a custom cauldron though? You could create new magical ingredients and have a range of potions sims can brew after collecting ingredients, perhaps either from around the world or by growing them from purchased seeds, or both!
I'm thinking each potion can have different moodlets and effects like the teas! Perhaps even a Harry Potter Polyjuice inspired one that allows you to take on the appearance of a sim of your choice!
Even prank potions would be pretty cool!! Imagine spiking a sims drink and causing them to fall into a deep sleep or some other crazy effect. Following on, some potions could be for light magic and some for dark magic!
I know it sounds like a lot, but with your talent and dedication I'm sure you could execute it perfectly! It would be a great addition to the mod!