other than compression and maybe weight. Are there any differences between these rotors?? Seals, Bearings, etc.

Nope, same seals, bearings, gears, etc.

They actually weigh the same amount.

mazdatrix states that the 86 - 88 NA rotors have a CR of 9.4. and the 89 and up TII rotors 9.0. How much of a difference would that .4 make if using Turbo rotors in a NA application??

Yea I second that. No weight difference in the rotors from a NA or turbo charged rx7.

No weight difference between the two, however different rotor weights, classisfied from A to E.

s4 and s5 rotors do weight differently, s5 weighs a little less but with higher compression. YOu can use either as long as you use the right conterweights.