Yeah, I'd love for a zoo game to acknowledge relations beyond sibling, parent, and grandparent.
My ideal zoo game would have more consequences in general for lots of things, you know, add more of a challenge along with more realism. Your accreditation would be threatened if you obtain animals from questionable sources. And even if you don't care about accreditation, it could result in bad PR. If nothing else, animals from questionable sources would be more likely to have issues. Krazy Karen's Discount Exotic Animal Warehouse may offer tigers at a low, low price, but there's a high chance the tigers would be sickly or inbred. When you use certain types of animals in shows or interaction programs, (riding horses or elephants, swimming with dolphins, training sea lions, that kind of thing) if the animals are unhappy there would be a risk of the animals attacking someone, and that would be a PR disaster. (hey, it's not a good simulator game if there's no potential to hurt people!)
One of the biggest problems with the family relationship record is if a female gives birth, the father of that baby assumes paternity of all her offspring (if they don't already have a father listed). This means a newly imported male cannot breed with a mother/daughter combination long term like they could in real life.
Yes I definitely agree with some realism in human/animal interaction! No more "Ouch, I've just been attacked by Bengal Tiger 79!" when the tiger has gripped the guest in his jaws and shaken him. Also the animals are remarkably sexist, they only attack men in ZT1!
If a keeper enters an enclosure with a dangerous animal, the animal should be called into a holding cage/indoor area automatically. The animal should not become unhappy on the happiness metre and flood the message screen with complaints if it is confined to anything less than a full sized exhibit for a few minutes.
I also hate when a guest somehow gets into an enclosure and the zoo keeper runs around crating everything in sight, even when I have removed the guest.
I do however find it somewhat amusing to see a ZT1 penguin eat an entire herd of elephant, giraffe or hippopotamus.
Good idea about animal's mood/behaviour affecting performance in shows etc. In real life, certain individuals are more likely to attack trainers, or be faster learners than others so this should be varied in the game.