It depends on the look I'm going for with honey, if I want some major darkening/caramelization, I add it at trace but if I want it to stay a bit lighter I add it after the cook and the batter has cooled some. I use fresh honey.
For good incorporation, I would add the clay or Oatmeal at trace. That way it's all mixed as long as its going to be in the entire recipe.
Depends on how thick your soap is at the end. If you are mixing in your scent after the cook (which you really should do with hp) then you need to get that fully incorporated too, so you're giving it a good stir anyway