1. Morality and truth CANNOT be determined via the evidence, FIRST you need a worldview, you cannot evaluate whether an action is right or wrong unless you have a worldview determining what it means to be morally right or wrong.
What is morality? Once we have a definition, then we can evaluate that definition in light of the evidence.
So if we can agree that morality is, or being moral is, pertaining to a system of conduct that defines right and wrong. Then all we have to do is decide what is "right" and what is "wrong". In a broad sense "right" are things that lead to health, well-being and happiness and avoid pain, suffering and misery.
If we can agree on that, then we can look at actions that lead to one of these two groups in light of the evidence for them.
Insofar as your second and third statement. No reason to be snarky.
......the truthiness of a claim is proportional to it's truthiness".
In regards to this statment, you correct, but what you really done is express a tautology. Not very helpful...
Like saying; The closer something is to being blue, is blue.
There are ideas and concepts that that are true, but defy our experience of the world and often run contrary to our intuition. That is where evidence comes in. It is a guide to finding truth, even if it can never actually get there, it points us in the best direction.
I believe we've debated the existence of god and we always run into the problem of history. You think (please feel free to correct me if I mis-speak) that history proves that certain actions took place and conclude that god must in fact exist. I reject your claims and come to a different conclusion. Not that god doesn't exist, but that I haven't seen evidence that would demonstrate to me that he does.