What if there were "schools" of training for the Investigator class?
What I am envisioning is a set of abilities I guess more or less set up like an Oracle's Mysteries or a Ranger's Combat Styles. Each of the schools would have its own specific set of skills that can be used for the Inspiration class feature.
I was inspired (LOL) by an episode of CSI and all the jobs that the characters there do.
For example, there could be a school like the lab/forensic technician that specializes in alchemy, receives options for mutagens (both mental and physical), discoveries, and gets the poison abilities and resistances with the possibly of bombs as an offensive balance.
Another school could have more of a SWAT style feel to it and have abilities built around teamwork feats and doing specific tasks along with assistance from allies, ranged weapons from being hidden, and have a sneak attack progression.
The last school could be built around tracking and have terrain mastery and the same tracking theme as a ranger. Heck, throw in an animal companion or a familiar-type creature option; that would be awesome. Perhaps a blending of alchemical uses of non-magic items like the Footprint Book or the Portrait Book as tools or as an alternate focus for an extract. Maybe some divination spells as spell-like abilities? No sneak or bombs option here.
Just some thoughts on how to organize this class.... because it has so many possibilities. These kind of sound like archtypes though. My $.02