Those are all corporeal sources and would only do half damage. Any weapon, spell or other source of damage from a corporeal creature would be treated as corporeal based damage and subject to half damage rules. There are a couple of exceptions. A Ghost Touch modified weapon is an example of a non-corporeal damage source.
A ghost touch weapon deals damage normally against incorporeal
creatures, regardless of its bonus.
Also, any creature with an Incorporeal condition (whether temporary or permanent) or the Incorporeal Monster SubType would be another good example.
Creatures with the incorporeal condition do not have a physical body.
It can be harmed only by other incorporeal creatures, magic weapons or
creatures that strike as magic weapons, and spells, spell-like
abilities, or supernatural abilities. It is immune to all nonmagical
attack forms. Even when hit by spells or magic weapons, it takes only
half damage from a corporeal source (except for channel energy).
Yes, for some types of creatures. These abilities are found on sorcerer bloodline arcana and on metamagic feats that require being 6th or 7th level to take.
Undead
The sorcerer Undead Bloodline arcana makes your spells affect formerly humanoid undead as if they were humanoids.
Corporeal undead that were once humanoids are treated as humanoids for the purposes of determining which spells affect them.
The Threnodic Spell metamagic feat makes mind-affecting spells affect any undead.
This feat only works on mind-affecting spells. A threnodic
spell affects undead creatures (even mindless undead) as if they
weren't immune to mind-affecting effects, but has no effect on living
creatures.
Constructs
The sorcerer Impossible Bloodline arcana makes your mind-affecting enchantment (compulsion) spells affect constructs.
Constructs are susceptible to your enchantment (compulsion) spells as if they were not mind-affecting.
Constructs are treated as living creatures for the purposes of determining which spells affect them.
A similar ability is granted by the arcana of the 3rd party Constructed Bloodline.
Oozes and Vermin
The Coaxing Spell metamagic feat makes mind-affecting spells affect any ooze or vermin.
This feat only works with mind-affecting effects. A coaxing spell affects mindless oozes and vermin as if they weren't mindless, but has no effect on other creature types.
The 3rd party Vermin Bloodline's arcana makes you treat vermin as animals when casting spells.
You treat vermin as animals when targeting them with your spells. This can make vermin susceptible to mind-affecting spells, for example.
The Vermin Heart feat (available to druids) changes which spells can affect vermin, but doesn't seem to bypass the vermin's immunity to mind-affecting effects.
Plants
The Verdant Spell metamagic feat makes mind-affecting spells affect any plant.
A verdant spell affects plant creatures (even mindless plant creatures) as if they weren't immune to mind-affecting effects, but has no effect on other types of creatures. This feat works only on mind-affecting spells.
Best Answer
Pretty much - it's any spell coming from a corporeal source (you know, a dude).
Now, it can get more complicated than that with things that aren't just incorporeal but also ethereal. Only force spells affect them directly but there's a lot of spells (e.g. blink) that can be used to make someone ethereal/incorporeal and then it's fireball time.