HSS (High Speed Sync) is a radically different flash mode than regular speedlight flash. HSS flash units, in HSS mode, switch to becoming a continuous light, continuous for only the duration of the focal plane shutter travel (i.e, Not an instantaneous speedlight pulse). Continuous light (such as sunlight or incandescent light) has no sync issue, it is always on anytime the shutter opens. So continuous mode allows high speed shutters, called high speed sync, because there is no sync issue. HSS is anything BUT high speed flash, it is the opposite, fully dead slow, continuous like sunlight, which cannot stop any motion, but simply has no sync requirement.

HSS does have the fast shutter speed to help, but speedlight flash is faster than the shutter, and runs circles around HSS, in regard to speed or power. Speedlight flash duration depends on power level, and is tremendously fast at low power levels, perhaps 1/3000 second at 1/4 power, and perhaps 1/30,000 second at 1/32 power level. It is called "speedlight".

The point of HSS would be to allow a fast shutter speed so that maybe f/2.8 would be possible with flash in bright sunlight. But the power range is limited.

Auto FP is just Nikons way to enable HSS. If you set 1/250 Auto FP, then 1/250 is still speedlight mode, but any faster shutter (allowed then) is HSS mode. Saying, if the camera recognizes the flash is present, then the shutter speed will not be allowed to go faster than speedlight sync speed. But in Auto FP, it will, and will become HSS mode then.

Both the flash and the camera have to be compatible about HSS. That leaves out any wireless radio trigger. Except the Nikon Commander can do remote HSS. But the real meaning is that regular speedlight mode and regular 1/200 second is likely far better, and works with the wireless trigger.

Here is more elaboration about HSS: http://www.scantips.com/lights/flashbasics2b.html