Okay, to sum it up in one word, what's the theme of my protag's story? Learning to think and act outside the box. Well, that's more than one word; but it's the best I can do.
About recurring themes---far from a liability, they're probably an author's greatest asset. They define her works so that readers know what to expect.
If a reader has already read and enjoyed one novel by a given author, she'll buy another with the confidence that the elements she previously enjoyed will recur in the context of a different story. That's what makes readers come back for more.
I've spotted three recurring plot patterns in my works. I've already mentioned one, about thinking and acting outside the box.
Another is: A falls in love with B, but can't figure him/her out. B is a complete enigma, which is part of his/her charm. But A has a huge, compelling reason to solve this mystery, and in doing so must deal with daunting obstacles and complications. Obviously this bit applies to my aforementioned story of Collen and Teleri.
The third goes like this: A is in love with B, but B suffers a cruel, bizarre fate. Now A must move heaven and Earth to save B. This pattern doesn't crop up in this story, but it does in quite a few others.
I can see why backstory usually matters, but in this particular narrative I don't see that there's any need to deal with it at any length or in detail. Collen's internal conflict stems from his devotion to his lord. That's a given in his culture, and my protag has no reason to think or act any differently---until he falls in love with Teleri.
Anyone who knows anything about the Middle Ages knows about the fealty of vassals for their lords, and how strong and pervasive these bonds were. And anyone who doesn't know probably won't want to read this story.