I'd be happy with allowing the Push in place of any unarmed strike. That sounds good!
Your rewording for Prone Fighting is good, too.
Ready for Spells, or is there another SA to add?
The Concentrated Push as is is ok. Did you want the "if that space is occupied, it falls prone" to apply to the defender as well? Right now, it looks like it only applies to the Keeper.
To make it a bit more appealing, we could add a bit where, if the defender hits an object, they take damage as if they fell the distance pushed. Or 1d6 hp damage per 10 feet, like the Snatch feat.
I think you're right abot the Incapacitator, but I can't remember where. Did you have any ideas?
I'll probably have to do a lot of rummaging to discover what the monster with that special attack was.
Will have a look, but won't make any promises.
Creature Catalog said:Shatter Bone (Su): Four times a day, a visceraith can try to shatter a limb-bone or jaw-bone of a single opponent within 60 feet. Shatter bone cannot affect boneless creatures, but can harm creatures whose skeletons are made of chitin rather than bone, such as most vermin. The opponent must succeed on a DC 16 Fortitude save or suffer compound fractures in the targeted bone, which inflicts 2d6+4 damage. Whenever a creature with shattered bones makes a move or standard action, it must succeed on a DC 16 Fortitude save or take an additional 1d4 points of damage. The Fort DC and damage increases by +1 for each extra limb or jaw bone that is shattered (e.g. DC 18 and 1d4+2 for three shattered bones). A DC 15 Heal check can immobilize a victim's shattered bones and prevent this additional damage. The save DCs are Charisma-based.
In addition to the damage, a shattered bone imposes the following penalties: a body part with a shattered bone lacks the Strength to hold and carry objects or make attacks, held items are dropped, but worn items are not dropped; if a shattered limb is used for locomotion (for example, a leg), the target's speed drops by three-quarters and Dexterity suffers a -8 circumstance penalty; if a shattered limb is used for manipulation (for example, an arm), the target's Dexterity suffers a -8 circumstance penalty and all spells with somatic components require a Concentration check (minimum DC 15); a target with a shattered jaw bone suffers a -8 circumstance penalty on skills checks requiring speech and all spells with verbal components require a Concentration check (minimum DC 15).
A shattered bone normally takes 2d4+4 weeks to heal naturally (half that time if DC 15 Heal checks are used to provide long-term care), but can be instantly cured with a restoration or higher-level healing spell.
The wording for push is good.
Concentrated Push looks good!
I think I'm revising my opinion on Incapacitator, though perhaps this interpretation is more boring. (It's much less complicated and doesn't require us to remove bone references, though!) The original Incapacitator says it works like the withering palm spell. In 3.5, that seems to function similar to a rod of withering --- a successful attack deals Con and Str damage, which converts to drain on a critical hit. How about we just go with that?
Oriental Adventures said:Withering Palm (Evocation)
Level: 7
Range: Touch
Duration: Instantaneous
Area of Effect: Creature touchedComponents: V, S
Casting Time: 4 segments
Saving Throw: 1/2
This spell acts similar to a staff of withering. Upon casting the spell, the wu jen must touch the victim. If a successful hit roll is made, the victim suffers 3d6 points of damage and must make a successful saving throw vs. spell to avoid the withering effect. If the saving throw is failed, one limb of the creature (either the limb touched or one randomly determined) becomes shriveled and useless. The head is not considered a limb! If the saving throw is successful, the creature still suffers damage but does not undergo withering. If an arm is withered, the character can still fight, though he cannot use two-handed weapons. Spells requiring somatic components can be cast 75% of the time. If a leg is withered, the character's movement rate is reduced to 1/4 its normal. Armor Class decreases by 3 and the character suffers a -4 on his chance to hit. A withered limb can be restored by the use of heal, limited wish, and wish spells.
Dungeon Master's Guide said:Staff of Withering: The staff of withering is a + 1 magic weapon. A hit from it causes 2-5 points of damage. If 2 charges are expended when a hit is scored, the creature struck will also age 10 years, its abilities and life span adjusted far the resulting age increase. If 3 charges are expended when a hit is made, 1 of the opponent creature’s limbs can be made to shrivel and become useless unless it saves versus magic (check by random number generation for which member is struck). Note that ageless creatures (undead, demons, devils, etc.) cannot be aged or withered. Each effect of the staff is cumulative, so that 3 charges will score damage, age, and wither. Aging a dwarf is of little effect, while aging a dragon could actually aid the creature.
SRD said:Withering
A rod of withering acts as a +1 light mace that deals no hit point damage. Instead, the wielder deals 1d4 points of Strength damage and 1d4 points of Constitution damage to any creature she touches with the rod (by making a melee touch attack). If she scores a critical hit, the damage from that hit is permanent ability drain. In either case, the defender negates the effect with a DC 17 Fortitude save.

(Dungeons & Dragons)
Rulebook featuring "high magic" options, including a host of new spells.