I never have celebrity on unless I'm in Bridgeport, possibly Starlight Shores as well depending on the game, it just doesn't fit with a country town like Riverview where I mostly play, if I could I'd just give it to Jon Lessen, he's the only one who fits the celeb bill there being a rock star in a big house.
As for annoyances my latest one is weddings, in sims 2 I always did the full works, wedding party, arch, champagne and it always went well. Sims 3 up until generations I mostly did private weddings but now with arches and cakes I do a party. This is where the annoyance comes in, it's not the guests as they do as expected it's the family who misbehave.
My first dynasty wedding all the in-laws literally stood up and turned their backs on it, then gen 2 just got married and once more the family stop watching and start wandering off, her mother and aunt both got phone calls so stopped watching to answer those, and her father started chatting to her uncle stopping him watching as well
I wish there was a watch wedding interaction you could use on them, if only so you can get pictures that don't look as if they are all leaving mid wedding.