While i agree in most of your post, we also have to consider that when amarr reaches lvl 5 on dropsuit armor upgrades (25% or armor basic HP) you will have 50 hp more than gallente meduim that also has that at lvl 5 for example (which is still less than a basic armor plate), they should add a low slot to all amarr suits, that would be more efficient, to give us an innate plate would be OP in my opinion, more if we get that bonus before sepnding ponts on the skill previously mentioned.
Most of you perspective is right, i like the PG reduction idea of the amarr SR but about the 10% heat reduction would be a mark that only SR is for amarr (which sounds logical) but not sure about this beain a good idea, they should have lowered the heat built up in general after the increase of TTK, at least a little bit.