SD card on AdaFruit HX8357 Braekout Board

I have acquired an Adafruit 480x320 touch screen display, which will be intertfaced to a Moteion Mega. On the HX8357 board is an SD card slot, which is nice, since I assume can keep images stored there. I'm going to use the SPI interface to talk to the HX8357, and apparently I use SPI as well, with a different chip select, to talk to the SD card.

Now I have never used an SD card before, but I've seen the code, and that looks straightforward enough (using the SD library). But I have four questions concerning this hardware.

  1. Is the SD card just on board the display board, but entirely controlled from the attached microcontroller?

  2. Other than chip select, I see a card detect pin designated on the display board. Is that essential to the SD card wiring?

  3. Are any other pins, besides CS and possibly card detect (and the other SPI pins) needed?

  4. The Moteino Mega cannot take 5 v. on its SPI pins (else the internal radio goes south). The HX8357 can be powered with 3.3v. or 5v., and is compatible with 3.3 or 5 v. logic. But if it powered with 5 v., does it operate at 5 v. logic levels?

Thanks in advance for any information.