No the two protagonists can't meet, but I have considered it in earlier versions. At this point the game's fairly hard coded towards keeping their routes separate. I generally try to avoid adding "bad" endings, even the one in Girlfriend Saves the City was eventually removed. Before the queen and cauldron, Monster Monsoon had a rather simplistic ending with text variations based on how well you did so there were some good and bad outcomes there. Secrets of the Bastion is the only game I made that has a game over failure scene, and I guess there's one ending in Summer Sweepers that you get for deliberately failing the tutorial maps.
The whole reason why I set up the gallery on the phone was because I already had event tracking in place on the divination app so I could show the requirements and the picture in one place. Changing it over to something else is definitely too much work and would probably make it much harder to find scene requirements.
If you ran out of popularity in older version you'd get a simple gameover screen and had to start over. There wasn't any sort of special scene like in Secrets of the Bastion. In the current version you can't advance towards victory and get fewer construction options if you're ranking too poorly with the public, but you can't lose the game.
Since the battles felt complicated for many players and a few events required losing to an enemy at some point, I decided to make it impossible to fail completely.