Here is the latest installment of my entities posts.
For those who have been following along it's all probably starting to come together about how the planes operate & what constitutes the various "powers" of those planes.
In this particular post I have lumped both IV & V together as both are pretty short.
Larvae are true entities though completely unintelligent where as thoughtforms are not an entity in the true sense but CAN become so.
Duskshade I will also try to answer your question about elemental energy that you originally asked in part I. as this fits into the thoughtform section.
Larvae are simply astral scavengers. I should specify lower astral which in effect means that they are etheric entities. They have roughly the intelligence of a lower order of animal. Perhaps a fish would be an adequate example of their intelligence level.
They are the astral equivilant to vultures or maggots. They recycle useless etheric energy to be reused for an emerging lifeform of somekind, be it physical or non physical. These entities are not evil though they can be harmful. They can mainly be found around graveyards, funeral homes or anyplace where the dead are. They also have a tendancy to hang around nursing homes or other places where the inferm or dying reside.
I suspect that orbs are actually larvae though I have no proof for this as I have never dealt with them. Classicly larvae are supposed to be the souls of evil people but in the context of the Western Mystery Tradition this is not the case.
As I mentioned earlier they can afflict the inferm or the dying. This is true but it is relatively rare. Magicians have been known to use them to attack there enemies as well but I will not get into this.
Essentially larvae feed off of the etheric bodies of the dead & break down the patterns of the previous owners mental & astral patterns to which the etheric body has been formed into a pattern of. This allows the etheric substance to be reused for something else.
There's not much else that can be said except that in relation to hauntings they could be present in a dwelling and cause people to get sick. If there were no other phenomena happening in the place I would assume that it was larvae that was causing the problem.
For the most part, thoughtforms are the mental constructs of other living things. Humans have thoughtforms around them all the time & this would account for any thought that seems to keep popping up over & over in an endless loop. Ever had that song stuck in your head? That's a thoughtform.
Even when these thoughtforms continue to exist for many years, they rarley attain a will of their own, but they can do that & become an actuall living entity. Usually though this is done by a magician for a certain purpose & then it's destroyed after the job is done. If a magician were to leave a consciously constructed thoughtform running past it's finished job it will continue to "feed" from the magician. Gradually it will take on a life of it's own & can be very hard to put down after that.
Artificial elementals are thoughtforms but they use one of the philosophical elements as it's basis. In answer to Duskshades question, you could have an elemental share some of it's being with you to construct an artificial elemental but it would be much simpler to merely construct it yourself.
In general a thoughtform is used to bring ideas or thoughts to someone to accomplish a purpose. In essence manipulating the individual by putting thoughts into their heads. They of course assume that the thoughts are theirs and can act on them as such.
The only time that this would be approriate without getting someones permission to do this is if they are very close to you & you are only reinforcing a persons normal thought pattern. Even then it must be used with discretion. Other times it would be merely manipulating the individual & that of course is wrong.
As far as haunting phenomena go, it would be very hard to distinguish between an actual entity trying to put thoughts into your head & a thoughtform that for some reason is just lingering. If you have extremely alien concepts come into mind that MAY be an indicator that there is something more than just a thoughtform, but if an entity is truly going to try and manipulate you it will most likely do so by putting more amicable ideas into you so as to not have you reject them as soon as you encounter them.
Again not much more can be said about these things.
As usual I will try to answer any questions.
Seek the truth & do not decieve thyself with falsehoods or thou shalt never learn