Yeah, I agree.
As you said, MC's rank is still at the bottom, issues with the DeLuca family members still need to be addressed, as well as MC's own family. And there's also the fact that only half of the Serpents are introduced, rest of the Big Five (of major Crime Families haven't appeared), not to mention conpiracy behind the Myserious 6, the past of Cordia, MC's mom etc and so much more story to tell.
I prefer long titles as well, because I like the whole journey of it all, the struggles, joys, sadness, anger and many emotions that MC and these characters that surround him will experience just makes it all worth it.
I think in terms of fear, mine is a bit different from yours.
It isn't really fear of Hopes not completing the game itself, but rather the fear of this game being suddenly rushed to the ending at one point in the story that just makes the flow of the story unnatural, and makes it seem obvious that the Developer suddenly ran out of ideas (I won't name the games, but there's at least 1 or 2 out there which I played that really suffered from this).
So my hope is that even after long time has passed with this game, Hopes still remains just as passionate with this game as he was in the inception of DeLuca, and now (because Devs just rushing their ending because they just got burnt out on it, and wanted to do something new, i.e. create another game instead.", it's always sad to see).