I love hemp oil and use it when I can, even if it IS a butt about short shelf life and risks of DOS. If you decide to keep hemp oil in your inventory, add some rosemary oleoresin extract (roe) as soon as you open it, and keep it sealed in the fridge and it will be good for up to a year if your bottle is fresh. I've made several hemp soaps that lasted 6 months to a year before developing DOS but that's about all you can expect. If that recipe speaks to you, its not a bad one to start with. For myself, I'd lower the coconut oil to 15% and make it up with the hemp and olive oil. I would also ditch the titanium dioxide and just use the clay (because I like clay in soaps - I would mix it with the lye water to be sure it hydrates), and ditch the organic matter on the top which just clogs the drain. But that's just me
And yes you can infuse any oil you like with just about anything you like - just strain it well before using. I cant think of an example where the SAP value would change. Unfortunately in my experience the only things that survive lye is color, and sometimes not that either. But it wont hurt.