I'm pretty sure this hasn't been requested before...
Something I would like would be the spells to be better. This is the list I have put together, but it's not perfect.
Beautificus Locus - I would like garbage to be removed as wellm just to make things easier.
Creatum Insecto Volucris - Should have a chance instead of rain to make it start snowing.
Tempus Interruptus - I don't like that after a while time starts again, it should stay off until my sim casts the tempus resumo spell or leaves the lot.
Inflammo - Should be able to be cast on a sim/object.
Heavus-Ho - Should inflict a sim with a random disease.
Not sure if these could be done, but I hope they can!
EDIT: I have all EPs and Celebration Stuff