Are you saying that you would modify the first definition of rational to include these >> other ways of knowing (Occam's Razor and Inductive Bias), and that they can make conclusions about metaphysical things?

yes, I don't think you can get far at all without an induction principle. We could make a meta-model of ourselves and our situation and prove we need induction in that model, if it helps people, but I think most people have the intuition already that nothing observational can be proven "absolutely", that there are an infinite number of ways to draw curved lines connecting two points, etc. Basically, one needs induction to move beyond skeptical arguments and do anything here. We're using induction implicitly in all or most of our applied reasoning, I think.