from what I know about Goku, I've always assumed he's a breath player, dude just wants to fight strong people as well as get stronger himself, doing good in the process is more of a side effect, like how the e-zodiac describes the breath bound as working, I'm not sure about the class though

I actually like Breath for Goku- Heroic Protagonist, but what you mentioned, but also, the detachment- That aloofness I mentioned before. Yessss.