For me I think the focus has always been too much on building and not enough on zoo management. The management always seemed too easy to me and they have things like diseases that in franchise mode don't really seem to do anything. I don't think I've ever imported a diseased animal in franchise into my zoo and so long as you keep things clean every animal stays healthy. Give me drama and things to sort out.
I'd also like to see more focus put on the animals in terms of them acting and feeling like individuals - a lot of the time they do feel like props. More things like animals having opinions on others in the group leading to different behaviours (including occasional fights just because they hate each other). Animals having favourite foods and toys. Animals having opinions on other species in the habitat or the guests. Just make them feel more real and less like replaceable props. Animals in zoos in real life, especially intelligent ones, absolutely have distinct personalities.
You nailed it. I am craving for an update that would change or add to the management aspect of the game.
Managing your zoo is just too easy, and therefore it becomes meaningless. I'm all for having different difficulties of playing, but I'd like to have challenges - I want things to go wrong and then trying to figure out how to fix them. The following things apply mostly to franchise and challenge mode.
1. Money/CC - it is absurdly easy to earn money/cc even in hard mode. And that's even without changing the salaries of employees, giving animals tier 3 food and keeping shop prices as they are. Once you get to a certain point you're practically playing sandbox.
2. Animal interactions/personalities - a requested feature is animal personalities which would add another layer(s) of animal management (e.g. find a suitable mate for your aggressive Bengal tiger) and habitat design (e.g. you have a very shy ostrich that needs lots of hiding spots)
3. Animal availability - you can practically have a giant panda right out of the gate. That's...not how it works. Obtaining animals is just too easy, and if you have amassed enough cc you can afford to buy pretty much anything. Animals should be locked behind completing certain tasks.
4. Research - as of now, research is just kind of there. You drag your vets to the animals you want to research and just let them do their thing, and voila, after 15 minutes you know everything about the reticulated giraffes. I don't really have an idea how to better this area of the game, but I'm sure some improvements could be made. (the same goes for mechanic research)
5. Specialized Keepers/Educators - I would love to see this. You have a keeper who works with the lemurs. After sending them to a very expensive program, now they become Lemur Keeper Tier 1 (for example it would go up to Tier 3 which would be the most experienced keeper). Not only you had to earn money for the training, but your keeper is now locked to lemurs and cannot take care for, lets say, Bengal tigers. But now also your lemurs are happier because their care has improved because they have a specialized keeper. Same would be for educators.
These are just some things of the top of my head. I love to build, but the building side of the game is so fleshed out compared to the management side, and I'd love to see more improvements for those who play franchise/challenge mode.