Well, I agree with your feeling that infused oil is kind of pointless in cooking where the herb can just be added during cooking. Infusion is the extraction of essential oils in the base oil, rather than bits of herb floating in oil. The infusion is useful for dressings, since it coats all the salad components with essential oils carried by the base oil. Unless you are going to use it pretty much all your salads, I don't know that its so much better than macerated herbs mixed in oil that it's worth trying to keep around or the two weeks it takes to infuse.
"Kitchen duty is awarded only to those of manifest excellence..." - The Master, Dogen