Before you post the demo, let us try a couple of things...

But firstly, now I am more awake, I notice that all 3 of the 'trace-from'
vectors will always be the same value, because they are the same point.
so cut that down to one calculation and use it in all three traces to save CPU.

Secondly, when you say you are 'playing with the distances', what do you mean?
Revember the trace-to vectors MUST have thier Z value = my.min_z before the
vec_rotate and vec_add otherwise the trace will start going
'uphill' or 'downhill' from the feet.

Or did you want the traces to go left/right/back from his feet but scan parallel to the ground?