black beauty

Just like the tittle says. Im a noob to the rotary but im learning fast ( picking up 3rd gen rx7 friday ) and i hope i can carry my knowledge of performance over from owning my dsm. And of course i have a few questions.

1. After reading up and such, i see that the power fc is a popular ecu upgrade. So my question is, is the stock ecu limited that much that i need to buy the power fc or am i able to throw a piggy back such as an afc?

2. Also i cant find much info on how much i can max out the stock twins. Like how much boost i can run with them with the proper supporting mods befor im blowing hot air and they are operating out of their effiency range.

3. And last but not least, the dumb question, when doing an oil change, how muny quarts of oil does the roarty it take