They do have a hydration need, but it's hidden. We only notice it when they start wanting to get water. Just allow them to get water once or twice and they won't need to again for a long time (unless it's a heatwave in summer).
The coffee and tea makers are weirdly attractive to sims, that is true!
I haven't noticed anything about cupcakes, but I have noticed that when there is leftover cake in the fridge, a hungry sim will prefer to grab that than other healthy leftovers :)
The last update broke a lot of things related to food mods, so if this is bothering you, you might start by removing all food related mods and see what happens.
