As a single player campaign, I don't see running Ameiko as a PC as a problem.

Ok, what will fall flat is the "romance" system that comes with the AP, but that's just a minor detail I heard that some people find irritating anyways.

What you should be aware of, is that this AP also makes use of some "heirloom weapons" that are tied to beating the DR of certain bosses that will come up as part of the story. That should be taken into account, as well as how to rebuild and handle the other NPCs that are along.