+widescreen 1 doesn't do anything. Even if the command means something the FOV is locked.
So if you choose to use +szx +szy and use a 16:10 or 16:9 resolution (like anyone who has a WS display would want to do), note that you LOSE some viewing area off the top and bottom, and have the same horizontal viewing area as 4:3. Basically they chop down a larger image, so using a WS resolution in BF2 (and also BF2142 cause they are d*cks) actually gives you less viewing area.
So.. you got to use a 4:3 stretched, a 4:3 with black bars, or a 16:10 native but with lose of vertical viewing area (not sure how much or what % is lost, check screenshots).