The danger I see is how you'd define "True Good Emotions" especially when "Greater Goods" start getting into the mix. Is it True Love to kill yourself rather than live without the woman you love (Im looking at you , Billy Shakes)? Is Grief a "bad" emotion, or is it based on loss of Love that is a "good" emotion. Isnt Fear actually Good for us? Is it True Sacrifice to let your family die in the name of your religious beliefs? How about letting the world burn to save your little girl? How about killing your little girl to Save the World? All villains think they are the good guys and are doing the right things.
Once you strip away the specific characteristics of each emotion and corresponding emotional bane, all you are left with is "Strong Emotion that is nominally 'Good'" and almost anything can be justified as Good. Imagine, as an example, you had a superpower that only made Glowing Green things and cold not effect Yellow Things (Silly I know, it would never work, but go with me
) That is a specific effect with a specific, recognizable and concrete counter. What you describe with the emotions would be instead having the power to make bright green things but the inability to affect "dark" things... Anything can be dark, and dark things can be kinda bright; White can look like pretty damn dark grey in the right light, and a glossy black can blind you.
Does all this rambling make any sense? The point is that "True Good Emotions" seems like it's waaay too subjective and ill-defined to make work. You could say all Whites are vulnerable to all three "true" emotions we were given in the WOJ (True Love, True Courage, True Hope) and could even add specific other ones to the list (True Faith, True Fidelity, maybe True Empathy?) but to leave it open to any blanket "Good" emotion opens things up to a lot of opportunity for disagreements, philosophic arguments, etc.
0.02