Yes I am making assumptions (they're pretty open) about goodness and rationality. Or better: hypotheses. I advance them because I think theories constructed around them will ultimately cohere better with our most confident judgments and discoveries. Try them and see. By all means try alternatives and compare.

Circular bootstrapping is fine. And sure, the main reason rational thoughts are good is that they typically lead to good actions. But they're still rational thoughts - thus correct - even when they don't.