Filou (an I don't count mango, coconut and avocados) once swallowed a cooked jalapeno when he was a baby. He got a very bad hickup- all the little boy was hiccuping, not just his throat. I was VERY worried as it happened Saturday night of course but he was ok in the morning.
Tigris is good compared to that. The strangest thing he ate was a cold cooked potato. Without sauce
I think a bit of oil for a healthy cat is ok if it is not her standard diet. I would be much more worried with Milly's pieces of string.
Table manners: I am not sure such a thing exists for meezers.... or Abys. Why do you think Juni is called Juni-get-down. Certainly not because her mom never tried to teach her manners