It would depend on how big the batch was. An ounce would be about right for a 5 pound batch. I use a mixture of jojoba and shea butter in most recipes. With the other additives like fragrance, oatmeal, milk, honey, pumice, tea or coloring you need to use a little bit of something that will emulsify the oils into a mixture like castor oil or a squirt of glycerine. Make sure your slurry is well mixed before dumping into the cooked soap batter.
No the soap is not oily at all. Having the slurry ready to go makes HP much easier. Keep in mind the more liquid you add either has to be off set by using less water for the lye or you need to add something like oat flour or oatmeal to thicken it some. I use parsley powder to thicken my green tea soap.