The answer, is the Chosen were all bound in the Pit Of Doom. LTT faced the Dark One in the exact same location that Rand did, except it was fire.

The implication, is that RJ decided after New Spring that darkfriends would be mentioned in the exemption, but was never outright spoken until Nyneave's full Oath taking. He may have decided to show the change in the Oath is most likely an implication of the Black Ajah working to undermine the White Tower since their first appearance. Changing that particular Oath in that fashion would allow that kind of corruption.

The third Oath clearly states, word for word: Never to use the One Power as a weapon except against Darkfriends or Shadowspawn, or in the last extreme defence of her life, the life of her Warder, or another sister. As far as I can tell, all Oaths in the show are the same ones. What we saw Moriaine do in Falme in the show is consistent with her knowledge of two Forsaken being in the city.

The Oath in the books named both shadowspawn and darkfriends as exempt from being protected from direct attacks by Aes Sedai. It also states that an Aes Sedai can channel to defend herself and her Warder. and can channel to defend another Aes Sedai and her Warder if attacked by others, like the Whitecloaks. These are the only exceptions. Going by how Moiraine behaved in the show so far, this Oath is unchanged.

No. The Oath deals with Shadow sided elements. It lists the Shadowspawn and darkfriends. At the end of the day, the Forsaken were Aes Sedai that defected to the Dark One, and became his leaders that speak directly for him, and take their orders directly from him, too. They were called Forsaken, because they were trusted Aes Sedai that turned against the world, and are darkfriends that lead on the Dark One's behalf, that all made the conscious choice to turn. Figures that darkfriends 3000 years later idolise as mythological heroes. One was a world famous theologian and philosopher. Ishamael. One was a technological research scientist. Lanfear. One was a world famous clinical psychologist. Graendal. One was a world famous doctor. Semirhage. One was a world famous athlete. Sammael. One was a historian. Balthamel. One was a musical celebrity. Asmodean. One was a teacher. Mesaana. One was a lawyer. Be'lal. One was a banker. Moghedien. One was a biological research scientist. Aginor. One was a politician. Rahvin. One was a world famous diplomat. Demandred. All of them Aes Sedai from the Age Of Legends. All of them turned, because they wanted more than the world could give them. The Shadowspawn are not naturally evolved life forms. They were all built, except for the Fades. They are born of Trollocs. They were made by Aginor after his turn, using human beings and animals in genetic experiments. These are not good people. They are the sort of people even Joker would hate.

The Forsaken are the Shadow's leaders. The shadowspawn follow their commands, and the darkfriends follow them too. Moiraine knows that the Forsaken are in the list by default, since they command the two groups the Oath mentions. They are the example the darkfriends all aspire to be. You saw Ishamael's talk to the little girl, and how he used the interaction with the Trolloc to influence her. The implication is that being a darkfriend has no age limit. A little girl would do just fine as one, and expected to follow their oath of allegiance to the utmost as well.

I took it to mean that Rhuarc knows how to read body language really well. Not one of the Emond's Field Five could fake body language until much later in their lives. He was good enough to catch Lan and Moiraine on their inner thoughts too. It comes from being a chief, with a blood feud with the most deceitful clans in the Shaido. Which was also a clan that lived close by them.