On to belief on/in evidence: Is there evidence of that kind for every little thing one believes in? Is there evidence for "good" or "bad"? I mean, how can one maintain that all he believes in is evidence based, and still use words like "good" and "bad"?
Evidence only has to do with the state of the world and the things in it. There is evidence for and against every single physical fact of the universe, including facts like "what does X think about Y?", since that's really just a question about what X's brain is up to. Alot of the things we have "beliefs" about are abstract concepts - things that don't actually exist anywhere in the physical world. Our brains behave like they do, because we didn't evolve originally to handle abstract questions like that. Instead, our brains co-opt the original answering-questions-of-fact-about-the-world-in-time-to-not-get-eaten-by-lions brain circuitry to consider abstract questions. And the brain does so by treating abtractions like they were physical things in the universe that we could get evidence about and form proper beliefs on.
So, to answer the main question: It depends on what exactly you mean by good and bad. Without a perspective to define good vs. bad from (and a defintion of whether you mean "right vs. wrong" or "preferable vs. not preferable" or something else entirely), there's no way to say whether something is good or bad or neither. There's no objective Good that exists outside of someone's mind for us to examine and get evidence about. Instead, you have to look at people's mind and their thoughts (as inferred by the things they say and do or by introspection if you're just concerned about your own thoughts) in order to get a grasp on what
they think good and bad are. Since there isn't an objective Good or objective Bad anywhere to look at, those mental perspectives are the only things that the words 'good' and 'bad' could be talking about.
If you mean it in terms of preference, ie. "good" is whatever is preferable to "bad", then, you can only have evidence for what is good and what is bad respective to a given person's preferences, or toward any set of average preferences you want, subject to constraints like Arrow's Theorem and so forth. At least assuming all the preferences involved are well defined and not self-contradicting. And if you mean it in terms of "right" and "wrong", then you can have evidence about "right according to X" and "wrong according to X" where X is a person's morals, or a moral code of some sort, but those are really just fancy special cases of preference. I wouldn't really qualify either one as a proper belief, at least not in the sense used in "is there evidence for belief X?". It's certainly something that people think, and something they profess, but it's not something they think about the world, so much as something they think about their own minds and whatever else it is that defines their morality.
Of course, none of that is to say that there's no point in studying morality and ethics - people's minds have shockingly large amounts of agreement about what is good and what is bad once you get down to the brass tacks, so to speak. It's just that these are questions of psychology and cognitive science, not of simple and obvious fact like the apparent location of the Sun at dawn is. Minds are confusing, so morality, being a question about the mind, is also confusing.