I haven't read any PPC mishes that are entirely in first person, or any that are in first person at all, to my memory, which isn't saying much.

What I recommend though is for the mission to be done in a diary form, or, barring that, how you would write it in a report for the DoIA, just much longer. Report form would be the best, I think.
As for the crash test dummies, I advise weapons that work on ghosts and not physical form, or which can be selective on which realm it attacks.

On that note, I think an artificial Keyblade would actually be a great help here. It possesses the power to momentarily force a ghost (or shadow) into the normal world and make it physical, giving you enough time to hurt it. The spirit (Or shadow) remains attached to the thing they're possessing, however, and will return if not destroyed quickly enough.
Another way to go about it is the Avada Kedavra curse, since it leaves the body unharmed, but seems to destroy the spirit, if the Horcrux that was in Harry is any indication.
Other suggestions would be to use any psychic or dark-type Pokemon from the Pokemon continuum, a Ghost-Slaying Axe from the City of Heroes Continuum, an exorcising / depossession spell from Charmed / Buffy or the Light Arrows from Legend of Zelda. The arrows won't work by themselves, nor will the axe, but when used with the Keyblade or depossession spell, they'd be much more effective.