Alright, I got tired of swimming through whether or not the SD Card contained valuable info regarding the Droid phone or not, so I just called the Verizon Tech. Support myself, to see what they had to say.
Their answer was... drum roll please....
That the SD card contains NO files that require the phone to operate. He said that if you just format the card that it may affect some of the 3rd party apps that you have installed, but that it is safe to format your SD card if you feel the need to. Then he went on to explain that you would lose all of your pictures, music you had on etc.
So, there, I'm happy with that answer. So if I ever flash back to a stock 2.1 phone, I'll know it's safe for me to format my sd card.