Does the effect of Jaunter’s Slice have a duration and additional effects on the target besides a loss of body part?

Does the effect of Jaunter’s Slice have a duration and additional effects on the target besides a loss of body part?

1) the ability says just make a save vs damage but does not mention of the removal of the body part is negated

2) with a body part missing is there on going damage or other adverse effects to it

Ex: Teleport head adjacent to user facing away from both user and the owner’s body make.

A) Is the body Flat-footed to oncoming attacks?

B) Does separation of head from the body stop normal bodily functions like breathing?

C) Does the severed head still have control over the body like remote control?

D) Can you kick the head around like soccer ball or is it anchored to the spot it was teleported from?

E) Is the decapitated creature who cant see or possibly have no control over their body considered helpless and susceptible to Coup de’ Gras?