Have a strange feeling your picture is already over-expose even without the flash; use ND filter
Under shade is fine, but sometimes have partial afternoon sun. So these situations definitely adjust like siao.....
TTL is "through the lens", which is some sort of auto exposure for the flash. The flash unit fires a pre-flash, measures the amount of light bounced back, calculate the flash power needed to expose the subject, then fires using that flash power. SB-400 is TTL only (no manual flash power, only flash exposure compensation can be adjusted from the camera)
Bounce card is too small and will not contribute to softer lighting. When you want softer lighting, your light source has to become bigger, and has to be close to the subject. Putting a bounce card outdoors will waste flash power as the card will eat up some of the flash power. Even a Gary Fong Lightsphere will not help to enlarge the light source by much, and will not contribute to softer lighting outdoors. However, a Lightsphere or a dome diffuser will help to soften the light indoors IF the light is bounced off surfaces. Essentially, what these diffusers do is that they spread the light everywhere in the hope that the light will bounce off the surrounding walls and ceilings to spread out the light (enlarging the light source tremendously) and thus softens shadows. Outdoors, you're better off saving flash power and using direct flash if you don't have a reflector or soft box or something to enlarge the light source. I didn't know all of these till I saw some of the videos that Lumiquest put up...I popped on the dome diffuser every time I used the flash, thinking that it would magically soften shadows, but that is not the way these things work.
Watching LUmiquest youtube vids now. Thanks for the tip!!