Atmega328P-AU interfacing with an SD Card at 3.3 V system voltage

I've never made anything except 5 volt projects, but trying to connect an SD card, I think it might be time to test out a 3.3 volt system. I think the answer is yes to all these questions, but I just want to be sure:
If my Atmega328P-AU runs at 3.3 volts, I can just connect pins 10-13 (SPI) directly to the SD socket?.
If I run it at 3.3Volts, I'll need to flash a different Bootloader on the Atmega328P-AU than the one I use for 5volt?
I will need to use an 8Mhz crystal instead of a 16Mhz one?
I have an FTDI board I use to program my projects that has a 3.3V/5V switch, so I can use that to program it?
Thanks

SouthernAtHeart:

  1. If my Atmega328P-AU runs at 3.3 volts, I can just connect pins 10-13 (SPI) directly to the SD socket?.
  2. If I run it at 3.3Volts, I’ll need to flash a different Bootloader on the Atmega328P-AU than the one I use for 5volt?
  3. I will need to use an 8Mhz crystal instead of a 16Mhz one?
  4. I have an FTDI board I use to program my projects that has a 3.3V/5V switch, so I can use that to program it?

1: Yes.

2: If you switch to 8 MHz then yes. If you stick with 16 MHz then no.

3: The ATmega328P is not rated to operate at 16 MHz on 3.3V (you are supposed to use 3.7V or more) but many people push the envelope and keep their 16 MHz crystal on a 3.3V system with good results.

4: Yes.

Thanks!