Yes, they are just lower profile tires.
No, this is not an acceptable swap.
Yes, you can but know that your speedometer will show 61 mph at a true 60 mph. The vehicle will also handle differently.
P205/55r16
225/55R16
Yes, you can substitute 215/55R16 tires for 205/55R16 tires, but there are some considerations. The 215 tires are wider, which may affect handling and ride comfort, and could potentially cause rubbing against the wheel well or suspension components if the vehicle is not designed to accommodate the extra width. It's also important to check the vehicle's specifications and consult a tire professional to ensure compatibility and safety.
Yes.
245/55r16
Mazda RX-8
Sorry, no ca do.
NO, this would be a very bad swap. Your speedometer would read 57 mph at a true 60 mph, and handling, ride, steering, traction, power, and mpg would be adversely effected. A 195/60-16 would be an acceptable swap.
205/55R16 for the Z24.
p205/55R16