1. for an auto tranny, i would look into the jackson racing supercharger for the pt crusier. same motor, it should fit, give them a call. a turbo will work just fine, but you dont have control over rpms, so lag may be an issue (unless its a small turbo)
2.?
3. wings west makes one that fits, i dont know about any others
4.?
5. as long as you get the right side tires, and the right offset wheels, 17's will be great for you. it will stiffen up the chasis nicely, look great, and will still allow you to get some grip. again as long as everything is the right size, you should be fine.