Raw parsley may affect some cats electrolyte balance and may be harmful.
There apparently are no such herbs.
Yes. A sick kitten can make other cats sick.
yes
No. It might make them sick.
A katydid will not make a cat sick if he eats it. Cats can eat bugs without the bugs making the cat sick.
it was probably because it was the wrong brand of cat food for your cats
yes cats can get sick like people.
Yes, some cats can indeed get sick from drinking cream. Cats cannot digest lactose (found in cow's milk and diary) very well, and can become sick.
Cats and dogs do it to make themselves sick.
Yes, It can really make them sick.
Nope
They look like cats except they are sick. ;)