ok...
now if you want gun drawn in hands while WALKING not jogging or running all you have to so is set speed to limited in a waypoint and he will walk.. then if somewhere the AI is supposed to run again set a Waypoint with Normal speed
this works with vehicles too when set to limited they drive slowly
if you want gun on back set to careless
if you want gun on back but AI draws gun when shot at or spots enemy set it to safe
but leave it combat and set speed to limited to get Ai to walk while holding gun in hands aiming as if he was part of a swat team walking in a building watching for enemy
that should be understandable enough