You need novels to get more on his backstory, you don't need said extra backstory to get a good character, I only told you about it because you didn't seem to know and might want to, that's all. However, his characterization was enough in the series, I wasn't implying the reading was necessary.
You also don't need "a pay off" in the sense that you mean to be a good character. He's a very minor villain. However, I'll say that in a very short arc his character gives Shikamaru a better pay off than Thriller Bark's entire existence.
I'm respectfully not reading that Bible right now, I'm not that invested in the topic. From where I stand Moria is the one "major" One Piece villain I'd scrapt entirely and bring him back to the drawing board, and that includes East Blue villains and Foxy.