Routes guests take are not even close to being a bit logical.
For example going to one Cosmic Cow, realize that there is quite a long line and decide to leave the park altogether while there is another Cosmic Cow right next to the other not serving anyone.
Guests with low cash will try to enter an "expensive" coaster, which they can't afford and will first go randomly visit other rides above their budget before visiting an ATM.
I could go on and on giving examples, but it really annoys me that they act the way they do.
Peeps actually think fairly predictably. Once you get over trying to view them as humans and remember that they're aliens from the Planet of Coaster, it's easier to tolerate them and you can set things up more to their liking.
As regards your 1st point....
Peeps must always have a goal, a destination, in mind. They go through a rather complex decision-making process to determine their next destination, whether that is a specific ride, a specific shop, or leaving the park. Whenever they get to that destination (assuming it's a shop or ride), they either do that thing, think the queue's too long, or discover they can't afford it. Either way, their next step is to pick a new destination.
So your park has a couple dozen rides, several dozen shops, and an exit. Each of these is a valid destination. How does the peep pick any one of them? It appears that each option is given a weight, essentially making it relatively more probable than other choices. Rides are heavily weighted by their prestige and the travel distance to them, shops are ranked by the intensity of the physical need they satisfy and hardwired preferences for specific types, and the exit's weight starts very low but increases over time, modified up or down by the peep's happiness level. All of these weights are then converted into relative probabilities, and the peep rolls dice to decide on his next destination.
The thing about this is that no destination is ever a certainty, and the chance of any option is never zero. While a very thirsty peep might be very likely to go to a drink shop to fix that, there's always a chance he'll leave the park or go on a ride instead. It's possible, though very rare, for a peep to enter the park, pay the admission price, then leave immediately without going on any rides or to any shops.
As regards your second point...
As mentioned above, the probability of a peep leaving the park is pretty much a function of time. If the peep is generally happy, he'll stay longer and vice versa, but time is the main thing. Another important thing is that price does not figure at all into the choice of a peep's next destination. Price only comes into play after the peep has decided to go there, and has arrived after the trip, and then discovers he doesn't have enough money to buy that thing. So, the important takeaways here are that:
1) peeps don't realize they're broke---the desire to leave the park is a function of time, not money
2) ride/shop pricing has zero effect on their popularity
3) if you have a bunch of broke peeps wandering around, it's because you took their money too fast.
As to ATMs, only a very small fraction of all peeps will ever use an ATM. This actually makes sense because if you could make them all do it, you'd have unlimited money. In general, even if your park is heaven on earth, only a few percent of all your peeps will ever use an ATM, so basically you're only source of income is the money peeps bring in with them. The few who use ATMs are just lagniappe.
So you're playing for pocket money. Which means that your monthly income is NOT set by prices but by the rate at which new peeps enter the park, bringing new money in with them. All parks have a peep capacity, either set by the user or the "natural" capacity which is some multiple of park rating. Once a park reaches its capacity, no new peeps can enter until some old peeps leave. Because peeps leave as a function of time, the only way to increase the rate of new peeps entering, and thus to increase your monthly income, is to increase park capacity, so more peeps are leaving per month, allowing more peeps to enter per month. But the higher you make your park rating, the happier everybody becomes, so the longer they'll stay. So increasing capacity ultimately runs into diminishing returns.
