Hola, friends! I know, I haven't been here in a while, lol, but I thought I'd toss in my two cents;
I find that most story arcs are never finished, but the reasons for this are not complicated; if someone said "Let's grab HOW TO TRAIN YOUR DRAGON off the shelf and write the full thing out on RL!" -assuming that everyone thought this was a good idea- how long would it take to rewrite the story? Well, it would be done in about a week. What changed?
If you want a fantastic, successful story arc with a full resolution, then I would suggest that you plan the full story beforehand, assign a main character, villain, and then some supporting roles, then assign someone else to follow the story and sort of be a director, one who dictates things like (They've been talking too long" or "Let's have a storm show up" or "How about they all sit down to lunch," or, finally -and most importantly- "Let's move on to the next plot point in the story." (This individual needs to be privy to the full storyline, and SHOULD NOT HAVE A CHARA INVOLVED).
The reasons to do a story this way; You reach the end of the story and feel satisfied, everyone had a fulfilling role in the story, the arc doesn't get overly-complicated and involve more charas than you can possibly remember, there wouldn't be flashes back and forth between one character's rolling out dough and another's duel to the death, and, finally, it doesn't take five years. (I've seen a walk in the woods + conversation take about three years to write. No joke. Unless I'm mistaken, that thread is still running…)
The negative side to doing it this way is that some people like to just write and see how things come out. I admit it's an attractive prospect. Some people do not like organized arcs like this. In my experience, however, it's worked pretty well. Check out "Black Sapphire."
And… sorry. Drat. I was planning on writing a couple sentences then walking away. I got carried away, as usual. Anywho, I wish you guys luck with this. It looks like it may turn out really interesting