1) You might be surprised. IRL if you're a growing region it's very hard for a city to go bankrupt. IRL Detroit has been in a bad region, dominated by a shrinking industry, and overseen by a state which would rather it went away, since roughly 1970. And we managed to not go bankrupt until very recently.
2) IRL it's very complex to value sprawling cul de sacs of suburban development. When first built they're great because the people who live there are the kind of people who almost never need the government, and have a fairly good income. If they weren't both they wouldn't be able to afford to buy into a suburb. This means a miniscule tax rate is enough to run the city. Then life happens, and 50 years later you've got houses designed to standards nobody wants, owned by people who were too poor to move out, which means that a) they need lots of government services, and b) they can't pay for those services with the miniscule tax rate, leading to c) the City Manager scrambling around to save the city while the long-time residents are convinced that it's still an upper-income enclave. Quite a few very smart people have pointed out that it's much easier to build new suburbs then build a new Brooklyn because of the way the Feds give out grants..
But in a world where you don't have the Feds actively subsidizing suburban growth, and region is growing (aka: a world where the game is fun), then having a core of apartment buildings surrounded by no development makes sense because it cost as lot less per unit to build/maintain a small apartment building then a suburban neighborhood.
3) This is a game. IRL in the US most cities have no control over their schools whatsoever because those are run by an independent school board. That would be no fun. So is forcing the player to plan an expensive education system from the beginning. Which is why no version of SimCity would require you get the entire City within the radius of a High School zone before you could build industrial zones.
4) Again, this is a game. It's no fun if you can't get started building pretty quickly, which means that educated migrants are necessary.
Now if you want a more realistic (ie: much harder) game you can mod it. But unless you mod in some pretty nasty ethnic dynamics you;re never going to make it as hard as real life is for cities like Detroit.