The current interface is perfectly suitable to handle this. When you select a town, there is a bar on the lower right of the interface. This bar fills up when the population grows, and when it is full the town grows a level. It also shows an icon of a house, displaying what the current maximum population is due to housing. And a mouse-over shows you the exact numbers, for instance '27 people, 100 needed for next level, capped at 82 due to housing'. It wouldn't be very difficult to add a second icon to this bar that shows food, and a mouse-over that says '27 people, 100 needed for next level, capped at 50 due to food, and 82 due to housing'. And on a larger scale, the resource bar could show, from left to right, the current populatioin of your kingdom, current projected population growth, and food production surplus (i.e. how much your population could grow).
It being suitable does not make it advantageous. It's not the UI that would hinder this system, since the UI can be made to conform to any requirement of gameplay design. It's the gameplay design itself that's the problem. One-to-one food gets ridiculous when you have populations in the thousands or tens of thousands. You can easily get a few thousand inhabitants among ceveral cities in a Tiny map. What about when you're playing the largest map size and have 30,000? Or more?
You're also not accurately considering everything you'd have to keep track of.
For example, what if you're not food capped? What if you have 1,237 people, you need to grow to 2,000 and have just enough houses to get there, and have 1,020 food. You want your town to grow, which means over a number of turns, 763 food will have to be used as people come into your city to live. That means, when you're planning your second city, you don't really have 1,020 food. You only have 257 food because you have to be sure to leave enough for the first city to grow.
What happens when you're trying to manage more than two cities? Sure you could add more meters and notifications to the UI, and have half the city info dedicated to keeping track of population and food, but why? This system is vastly inferior to the current one.
I hope control is necessary. I hope that food will be scarce enough that you couln't grow every town you build to level 5, and wouldn't want to. And IMO there should be something to lose; materials, and living space when uprading to more luxurious levels.
It is already scarce enough. As I said previously, this would have a purpose in your proposed system, but doesn't make sense in the current system. Any non-permanent "loss" (like materials) is not a deterrent to upgrading a house, either. If you don't have enough, just wait a few turns. It is at worst a delay.
Yes villas are big, and in theory could house a lot of people. But what makes a villa a villa is that it is a luxurious and spacious house for a small number of people. If you let a lot of people live there it becomes some sort of community housing project. A very well build housing project, but still. By your logic, the best most expencive housing would be a giant warehouse filled with beds and whatever else you need to house a large number of people. I doubt a lot of people would call that luxurious living.
If memory serves, Villas offer a minimal boost in population over Houses. They do, in fact, provide a prestige bonus, and are more expensive. I find it odd that you have no objection to a hut somehow housing 32 people, or a normal house housing 64, where in "the real world" they can't come close to matching those numbers, but take issue with villas housing a lot of people even though of the three they're the only structure that is capable of actually doing so. And no, a warehouse with beds is not luxurious living, and that's why a slum, despite providing a large population bonus, loses your town prestige!
