I don't like any of them!
WAR = Do you really want to call something associated with the great WHDLoad WAR?
WARP = Term used when reading raw MFM data from a disk and storing it in a file. Therefore it will only confuse things if people have 2 names for totally separate things. Warpers have been around for donkeys years and therefore they should be allowed to use the name.
RAW = I also dislike this name as RAW is usually talking about the data from IFF picture formats after the IFF stuff has been removed. RAW is also a term some patchers use so this is also no good imho.
You said there were 4 choices but you only listed 3. I hope the 4th is better than the other 3! What is wrong with just calling it something generic like WHDLoad Dat (or WHDDat)?