Old high school - with some basic animation

My personal project. I have some issues that i haven’t found out the solution

  1. The fan’s animation looks quite funny, but i don’t know how to do it look better
  2. The leaf falling has kind of trail (look like the insect falling instead of the leaf falling), then I haven’t known how to remove it yet.
  3. At first I tried to make coffee bead drop, but it turned out looking like rain drop in the coffee glass, I just want a slowly drop of dense liquid, I tried many ways but nothing worked like I expect.
    I really appreciate your help or any recommendation for better result. Thank you all !