vodo40k wrote:You can wear power armour/tda without black carapace, however your movements will be significantly encumbered.
I wouldn't necessarily say "significantly" - this would imply that there is a huge delay in a suit of power armour reacting to any sort of input (which would include any commands sent by the Black Carapace). A better description may be that the Marine feels the armour as if it was a part of him, whereas anyone else (provided they do not have an MIU implant) may have to get used to "working with the suit". Perhaps it could best be likened to a person getting to drive a car for their first time: there will be a long period of getting used to how the car reacts to your feet on the pedals or your hands on the wheel, but after months or years you will get used to it. A Space Marine simply foregoes this period entirely.
The Black Carapace also has another, circumstantially more important feature in that it also controls the onboard medical suite and drug dispenser of the armour. Standard biomonitors are probably not as capable when it comes to reading patient status due to the reduced data they receive from "less intrusive" sensors (again provided the user has no special implant for this).
CthuluIsSpy wrote:Space Marines get a more advanced type of PA as well, IIRC.
Not more advanced, but more "decked out" in that it includes tons of gadgets.
That being said, every Inquisitor's armour is different, and it may well be possible that some Inquisitors have suits that feature even more/better stuff.