I'm currently playing Nathema Conspiracy and trying to find videos of walkthroughs and none of them show where I'm at? Is it possible there are two beginnings or whatever if you played A Traitor among the Chiss vs. if you didn't (I didn't)? Is playing Traitor actually necessary?

yes you need to finish copero story to progress in the story. if you haven't you play the version of the flashpoint that's available before and after and doesn't have the majority of cutscenes, the prologue and other bits.

The three flashpoints of the "Traitor" arc all have four modes rather than the usual three:

* [MASTER] is like normal [MASTER] mode. It is anonymised.

* [VETERAN] is like normal [VETERAN] mode. It is anonymised.

* [sTORY] is like normal [sTORY] mode but unlike the [sTORY] mode for the Forged Alliances flashpoints, it is anonymised, and is meant to be played solo (er, with your choice of companion, of course, but not with other players).

* [sOLO] is the special mode that each character can run through one time, and *it* advances the story. It is not anonymised.

 

The anonymised modes have an anonymous masked figure, called "Masked Figure" (I think), in place of the actual traitor, in order to conceal the traitor's identity and avoid spoilers.

 

To play [sOLO] of one of them, you must first complete [sOLO] of all the preceding ones, and before you enter them, you must carefully follow the on-screen mission objectives. For Crisis on Umbara, the first of them, you must complete the War on Iokath story, although running the Gods from the Machine operation is not required.