The medium for the Swan film is cellulose film and the medium for the Pearl film is video.
Both orientation films were made at the same time, presumably in 1980 -- indicated by the copyright date at the end of both films. Dr. Candle's differences in appearance and name are part of a deception of some sort.
It's not a very clever or well thought out deception if they're going to put a date on the films.
The Pearl is a mock assignment to keep Dharma members unaware of the incident in the Swan and the danger posed by its electromagnetic activity. Just as most Dharma personnel were unaware of the nature of the Orchid, they were told that the Swan was a psychological experiment that must be kept isolated.
Especially with the Hostiles to worry about, Dharma did not need any more problems to discourage potential recruits from joining
Specfically, the assignment could be for ex-Swan personnel to "brainwash" them into thinking the Swan was fake to keep it secret.
The pearl was there to make sure the swan workers were alright but to keep it secret they were told by dharma that it was a social experiment. This is why the logbooks filled in went no where because any major problems would have been reported up to a higher authority (maybe someone like Radzinsky) and therefore the logbooks were just there to convince the pearl workers of the swan being a social experiment.
The Pearl was originally used for the purpose stated in the orientation film. After the Incident, the Others realised that the Swan site needed to be stabilised by entering the numbers, but did not want Dharma using the station for experiments. An agreement was reached that the pneumatic tube would be redirected out to the jungle in Others' territory. This way, the Others could check notebooks at random to make sure no experiments were being conducted, without having to conduct intensive monitoring themselves.
The computer that Locke used to print out the log is a backup to the one in the Swan station. If the Swan occupants failed to enter the numbers, the Pearl occupants would be able to do so remotely. After the incident, the DHARMA Initiative saw the need to have a backup computer to prevent another.
Not likely. The computer seems to be a control equipment, rather than a backup one.
There is another computer of the same make in each of the other DHARMA stations. These are backups to the one in the Swan.
This could however explain Ben's story. The Numbers could have been entered remotely, making his story about pushing the button true.
When Locke initially explored the Pearl station, he noticed cigarette butts. This shows that someone was watching all the activities within The Swan at some (possibly recent) point in time.
Ben was the one inhabiting the Pearl; left and began his walk to the beach or the Swan when Rousseau caught him.
Ben has never been seen smoking. It's more likely that it was Mikhail, since he clearly knows of the station's existence, and was in charge of surveilence and communications for The Others.
It is named after Pearl City on the Hawaiian island of Oahu where LOST was filmed
In The Lord of the Rings series, the eye of Sauron acts like a monitoring tool, and can use Palantirs as glass eyes. 
The room is also similar to the Architect's room in the Matrix series, who explodes after Neo's visit. It's to be noted that the Matryoshka_doll doll was hidden there by Paulo, and that it's name is very similar to "Matrix".
The name is a hint to Desmond's foresightings, like a medium with a crystal ball.
A pearl is similiar looking to a crystal ball. A cystal ball is used to see things secretly, while The Pearl is used to watch the other stations secretly.
While the names of many stations seem to be related to Apollo from Greek mythology, the Pearl seems to be named according to a different unknown scheme. The DHARMA logos of the stations that do not follow the Apollo theme are inverted.
The DHARMA logo is reversed in color so that the pearl in appears white, the more common color of pearls.
The Pearl is a reference to Matthew 7:6. Knowledge of the goings-on of the experiments of the Island, what the 'guinea pigs' are doing and WHY they are doing it is knowledge reserved for those running the show, those who know what the big picture is. If the guinea pigs running the experiments found out what was going on and why they would revolt against their masters, which may have been the case.
He worked with Eko on the church and Eko had been to the Pearl. He used the books to make plans for the church and Charlie used the rest of it later.
But, didn't Eko give up building the church when he got back from the Pearl?
Yeah, but Eko said that Charlie should bring his stuff to the Swan. Eko took a lot of notebooks with him from the Pearl. I guess Charlie just asked if he could get one.
When Locke visited the Pearl station for the first time, he sees an enormous stack of notebooks in the cupboard. Talk spreads among the losties and Charlie says to himself, "I'll go get one," we just didn't see it happen.
The notebooks are intended to be a log which will be recovered by The DHARMA Initiative in case the experiments on the island go wrong. If the time travel experiment goes bad, or the Swan explodes, the project would be terminated and the gas would be released, killing everyone on the island. The notebooks are surviving records of all activity in the stations. DHARMA scientists (off the Island) can later retrieve the notebooks and read the entries to determine what went wrong with the DHARMA Initiative. The notebooks are like a "black box" for the DHARMA Initiative.
The above theory is improbable, seeing as the DHARMA Initiative would not have left such a crucial thing as a “black box” type item, sit out in the open, exposed to the elements, piling up in huge mounds. If this theory were true, they would have had the tube routed to a storage room, they would have also set up computers set up to record all the events of the stations, because they would not simply go on eye witness accounts alone. Although the theory about the Tempest being specially set up as a failsafe mechanism is probably accurate.
The pneumatic tube dumping on a clearing rather than sending the reports to some headquarters strongly implies that the people in the Pearl are the subjects of the psychological experiment, not the members of the Swan.
It could also be that reports were dumped there for later easy pickup, but the post was later deserted.