If you buy a new car that has stock forced induction, the motor is built around the turbo/supercharger, so in other words, the compression is different, and the internals are different to withstand the pressure, and other things like hotspots and such.

It sounds like a Subaru WRX would be a good car for you, it is a very nice daily driver and good on gas, and you have the option of many different models and motor size and turbo or no turbo. Also its all wheel drive...

The questions you ask are not specific to a certain car, so they are hard to answer.

- what do I have to expect with a turbo from a longevity and maintenance standpoint?
A- That depends on many things: How much boost you run? How the car is driven? How you drive the car when you drive it?

- how long do turbos last before needing servicing? and what does that involve?
A- On average a turbo will last the life of the motor, as long as you do regular maintenance, and dont run a crazy amount of boost all of the time. Turbos are water/oil or just oil cooled, and heat is the #1 cause of parts failure. So as long as they stay well oil'd/cool'd then it should be fine. After a long peroid of time, you will start to get shaft play, and if you desire, you can get the turbo rebuilt, or buy a new one.

does it increase breakdown of the piston rings or any other internals? (compared to just VTECing instead)
A- That depends on: If it is a stock turbocharged car, or if you add a turbo to a motor that was not designed for forced induction. Also VTECing is not a word, I would recomend doing some research on Honda and (vtec) and finding out what it is befor you get the crap flamed out of you on this forum...

with more mechanical parts and a more complicated system, how much more often does something break? (assuming the same driving conditions if you didn't have the turbo)
A- Again this depends on: If the car comes stock with a turbo, or if you add a turbo to a motor that was not designed for forced induction.