Sneak Attack and Critical hit Creature Archetypes

I have re-checked the critical hits and sneak attack for pathfinder and found there exists only four creature types and one magic item that makes a creature immune to critically his/sneak attacks. This includes
1) Oozes,
2) elemental subtype,
3) swarms and
4) incorporeal subtypes.

The magic item that provides protection is an armour or shield item of fortification, wither 25%, 50% or 100%.

So this changes from normal 3.5 in that aberrations, corporeal undead, plants, outsiders and constructs can all be sneak attacked/critically hit. Although this has not significantly impacted the 1st campaign due to all forms of undead being incorporeal undead, it will provide a large booster to rogues in future campaigns. Furthermore incorporeal undead can be critically hit/sneak attacked with ghost touched weapons. This has not impacted the Haunting of Harrowstone in a great way, in that most large scale fights that took place included undead with incorporeal subtype. Furthermore such battles did not result in party deaths.

I will show an example below read the bold section

From p309-310 bestiary
Undead are once-living creatures animated by spiritual or supernatural forces. An undead creature has the following features.
• d8 Hit Die.
• Base attack bonus equal to 3/4 total Hit Dice (medium progression).
• Good Will saves.
• Skill points equal to 4 + Int modifier (minimum 1) per Hit Die. Many undead, however, are mindless and gain no skill points or feats. The following are class skills for undead: Climb, Disguise, Fly, Intimidate, Knowledge (arcane), Knowledge (religion), Perception, Sense Motive, Spellcraft, and Stealth.
Traits: An undead creature possesses the following traits (unless otherwise noted in a creature’s entry).
• No Constitution score. Undead use their Charisma score in place of their Constitution score when calculating hit points, Fortitude saves, and any special ability that relies on Constitution (such as when calculating a breath weapon’s DC).
• Darkvision 60 feet.
• Immunity to all mind-affecting effects (charms, compulsions, morale effects, patterns, and phantasms).
• Immunity to death effects, disease, paralysis, poison, sleep effects, and stunning.
• Not subject to nonlethal damage, ability drain, or energy drain. Immune to damage to its physical ability scores (Constitution, Dexterity, and Strength), as well as to exhaustion and fatigue effects.
• Cannot heal damage on its own if it has no Intelligence score, although it can be healed. Negative energy (such as an inflict spell) can heal undead creatures. The fast healing special quality works regardless of the creature’s Intelligence score.
• Immunity to any effect that requires a Fortitude save (unless the effect also works on objects or is harmless). • Not at risk of death from massive damage, but is immediately destroyed when reduced to 0 hit points.
• Not affected by raise dead and reincarnate spells or abilities. Resurrection and true resurrection can affect undead creatures. These spells turn undead creatures back into the living creatures they were before becoming undead.
• Proficient with its natural weapons, all simple weapons, and any weapons mentioned in its entry.
• Proficient with whatever type of armor (light, medium, or heavy) it is described as wearing, as well as all lighter types. Undead not indicated as wearing armor are not proficient with armor. Undead are proficient with shields if they are proficient with any form of armor.
• Undead do not breathe, eat, or sleep.

As you can see above ‘NO WHERE’ does it say an undead creature is immune to criticl hits/sneak attack

Instead in the bestiary it states;
• Not subject to critical hits or flanking. Does not take additional damage from precision-based attacks, such as sneak attack.

Elemental Subtype
• Not subject to critical hits or flanking. Does not take additional damage from precision-based attacks, such as sneak attack.

Incorporeal Subtype:
• An incorporeal creature has no physical body. An incorporeal creature is immune to critical hits and precision-based damage (such as sneak attack damage) unless the attacks are made using a weapon with the ghost touch special weapon quality. In addition, creatures with the incorporeal subtype gain the incorporeal special quality.

Swarms Traits::
• A swarm has no clear front or back and no discernable anatomy, so it is not subject to critical hits or f lanking. A swarm made up of Tiny creatures takes half damage from slashing and piercing weapons. A swarm composed of Fine or Diminutive creatures is immune to all weapon damage. Reducing a swarm to 0 hit points or less causes it to break up, though damage taken until that point does not degrade its ability to attack or resist attack. Swarms are never staggered or reduced to a dying state by damage. Also, they cannot be tripped, grappled, or bull rushed, and they cannot grapple an opponent.

Sneak Attack and Critical hit Creature Archetypes

Carrion Crown: Kyle's ktle1985