Nindl, I forgot to say how awesome your ideas. My original message was a jumbled mess and I must have deleted that bit when I was trying to streamline it.
Sally, since I grew up on a farm I would really love to have a farm pack. I liked the chickens and cows from the Sims3 Store, but they couldn't really interact much. I raised chickens and they like to be petted. Roosters hate the color red-- I had one who would charge at us and jump in the air and kick at us if we wore red (so we would have to use trash can lids as shields).
I've had rabbits as pets before too. Rabbits liked to chew through the wood on the hutch to get free. I had a very sweet lop-eared rabbit. I also once rescued a wild bunny (dogs caught it but didn't injure it) and raised it. Wild ones need a more specialized diet: Timothy hay. Carrots only as a treat from time to time. NO cabbage or lettuce as it can give them gas and rabbits have no way of passing gas and can die.
I also raised cows. Depending on the breed they can be docile and friendly, skittish, or aggressively playful. My first cow was the former. I bottle-fed her and she loved to be petted and was just very sweet. Current oldest cow is the latter. She thinks it's really fun to hop up and down, charge at people, and chase them. She doesn't mean any harm, it's just playing. Her daughter is the middle one. She's very skittish and nervous and doesn't want to let people get too close, but she's very affectionate with her mother.