Thinking it over from a writing perspective, I think it's not controversial to say that there are some stories which could be fleshed out better. Nothing wrong with open ends, of course, as it's something I especially like about Gensokyo. Not just for what fans do with the unanswered questions, but also in how they add a strong emotive element of mystery to the place. But there are some stories that, I guess, feel like strong beginnings that could lead to even better stories with exploration. While some stories end in one clean arc (IN), there are others that make me want to see the story explored further (PCB, in particular regarding Yuyuko). But even these two casts were explored further, in manga format. This is partly why I've been pleased with the religious arc, even if the games themselves have been a little uneven. ZUN does like to take his time with a narrative. Further exploration of the existing cast is something he actively does. I expect he'll continue to do this, even as new characters get folded in, and form relationships with these characters more further developed.
