I got a game today, and I've been trying to figure out a concept for them.
We've got two fighters, and a sorc (going dragon disciple) and a DMPC healer.
So it kinda falls to me to be an investigative character, which is kinda why I'm thinking kitsune, as the tiny fox shape is very good at investigations.
The campaign seems to be a lot of Call of Cthulhu.
Try the Bard archetype, Archaeologist.
You'll get all the knowledge fun of the Bard, plus plenty of crossover skills and talents from the Rogue. You lose the ability to Inspire, however, so you would need to concentrate on non-magical CHA interaction skills.
If you're not married to the idea of playing a Kitsune, then an Investigator would be pretty much perfect for what your party needs. You'd want to place a race with a +INT.