There used to be a publisher called Dire Press that did a series of really neat PDFs of d20/3.5e feats for ghosts. Unfortunately, while they are still listed on RPGNow, those PDFs are no longer for sale and
their Web site makes it sound like they aren't around anymore. It's a real shame too because I think these would be very useful for what you want, and wouldn't be that hard to tweak for Pathfinder either.
Chains of the Spirit had 19 "spiritual" feats for ghosts:
"Some ghosts spend their afterlife in quiet meditation instead of mischief
and malevolence. They study spirituality from a unique perspective,
pursuing a deeper understanding of their own nature and a heightened
awareness of the cosmos around them.
Chains of the Spirit provides nineteen new feats specifically designed
for such ghosts; those who desire to transcend their remaining ties to
the material world, expand their conscious minds, and seek enlightenment."
Chains of Shadow had 18 "umbral" feats for ghosts:
"Some ghosts are not content to lurk in the shadows as mere haunts and
corrupters. They peer deep into a twilight world, one that conceals
mysteries and powers beyond the knowledge or ability of the corporeal.
Chains of Shadow provides eighteen new feats specifically designed for
such ghosts; those who desire to dwell between light and dark, take and
shape the shadows around them, and master umbral powers of both
creation and destruction."
Chains of the Phantom had 18 "phantasmal" feats for ghosts:
"Some ghosts prefer deceit over destruction, control over corruption.
Their power lies in the strength of their mind, though not over matter.
They view telekinesis as a mere parlour trick, a wild talent fit only for
barbarians accustomed to throwing and breaking things. Instead, they
use their power to affect the minds of others, altering the perception of
reality itself to mislead and influence.
Chains of the Phantom provides eighteen new feats specifically designed
for such ghosts; those who desire to beguile the mind, deceive
the senses, and wield hallucination like a fine blade."
Dire Press also did a 37 page PDF called
Shroud of the Aether which included a ghostly "casualty" class of 20 levels:
"The death of a character. These words strike dread into players and
DMs alike. At best, the party has a cleric with raise dead prepared,
and the game can continue. At worst, the player is sidelined for the
rest of the adventure, until the party can return to town. But what if
there were some way to keep the character in the game and the player
involved? What if... she became a ghost?
The problem, of course, is that the ghost template grants a sudden and
major increase in ability. Pretty quickly, everyone will want to be one.
And what if they decide that they’d rather remain ghosts? Where do
they go from there?
Introducing Shroud of the Aether. Undeath, with class!"
In addition to the class and a discussion on playing a ghost and using the material in a campaign, there were some generic ghost feats, and more Chains:
Chains of the Aether feats ("The Ethereal Plane hovers above the material world like an echo, a formless void of swirling
mists and never-seen dangers, the province of ghosts. Ghosts who dwell there learn to cross its
boundary and exist in both the Ethereal Plane and Material Plane at once. Other ghosts learn
to dance at its edge, using the plane’s amorphous nature to alter their own apparitions, or to
instantly leap across space.")
Chains of the Banshee feats ("A banshee is a spirit of myth, the ghost of a beautiful woman who appears as a harbinger of
death. Her cry is sad and mournful, surely the sound of doom.")
Chains of the Coil feats ("Many ghosts exist because of something which binds them to the mortal coil, so it should
come as no surprise that they might wish to continue to interact with it. Most do so through
telekinesis, the ability to move and manipulate physical objects through sheer power of will.
Others achieve the ability to manifest more completely into the Material Plane, or to drag
objects or even other creatures into their incorporeal world.")
Chains of Corruption feats ("Some ghosts, whether through arcane lore or their own evil natures, wield a corrupting
energy which harms living creatures. The mere touch of such a creature can cause flesh to rot
or the mind to recoil and wither. A few ghosts can even cause such effects with nothing more
than a glance.")
Chains of Dread feats ("A ghost is evidence that even death can go wrong, and the sight of one is enough to fill a
living creature with dread and dismay. Some ghosts can amplify this effect, empowering their
appearance with supernatural energy to induce a crippling terror. Truly powerful ghosts may
cause such dread simply by charging into battle, or even by their mere presence.")
and Chains of Malevolence feats ("Of all the supernatural abilities of a ghost, perhaps none is so well-known or so much feared
as its power of malevolent possession.").
The whole series was really impressive, and it's a shame they aren't available for sale anymore.
