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.
225/55R16
P205/55r16
Mazda RX-8
245/55r16
Sorry, no ca do.
Yes.
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
205/55R16