I'd really like to see a complex financial model which really allows you to explore different ways of running your hospital. * Being able to meet pharmaceutical reps and negotiate drug prices * Designing and building car parks and deciding what parking charges are brought in * Adding a restaurant/cafe for staff and visitors * Deciding when and whether to charge to treat patients that don't have adequate insurance.
These are just a few ideas, I have many more for other aspects of the game.
Even a Public funding income if you fullfill some goals or conditions during some time. Example: you recieve during winter an amount every day wheter you cure flu or not, but every person cured don't be charged by you -a public funding. This can add some economic mechanics.