For installing a ROM, I understand you are free to do it from the internal or external storage - you just need to find the file from the recovery's file manager. No problem.
HOWEVER, instructions for this (and many ROMs I've read about) tell you to do a "full wipe" (data, cache and dalvik).
Does this mean I can't (shouldn't) install from internal storage? Or, what are the consequences of not wiping the data partition? Can it be wiped after somehow loading the ROM file?