Wait, WHAT?! Bracknell is going to do something to Aria?! Awwwww no. Yerbol is going to be maaaaaddddd xD

And then I read your stuff...ouch. Roan's gonna croak, eh? I like him. Ah well, such is the way of our space drama. Death does make things more compelling! 

Right, so to address your points: 
-That sounds like a good trajectory. I can see how after their visit to the Sith homeworld, the Masters + Ari and Yerbol realize that the Sith's goal is for total destruction of Force Users in an effort to "kill" the Force. This, obviously, is alarming. I assume that they would be able to get some proof(holos, scrolls, etc.) from the planet and get it safely off world while Bracknell hounds them. I also assume that even though Bracknell intercepts them, Roan and Matt can be an overwhelming enough Force to at least thwart Bracknell's initial attempt at squashing their rebellious movement and escape off the Sith homeworld. I think something that could help turn the tide initially is information warfare, which is where Neta's contacts would come in. They could release the information to the holonet instead of other sources, seeing as they don't trust anyone they know(they could be Sith). With the information out there, the Sith exert their powers of influence to maintain some control over the newly formed government, but more and more questions start getting asked. Defectors approach Neta's contacts and begin to send resources(including footsoldiers, agents, etc.) to help build up a resistance. This SHOULD take a while, so I'm thinking a few months of sneaky missions to take out important Sith targets to cripple the hold they have on the government. (we can do a time skip summarizing that time period)

-After ticking Bracknell off to the point of no return, he finally finds the base where the resistance has formed and sends the remaining forces he has on the planet. This is where YOUR sequence of events begins, culminating with Aria(with Yerbol's help?) defeating Bracknell. Yerbol will obviously get out of Aria's way to deliver the final blow. While this is all going on, Saresh has been mobilizing the resources she has to help stop the conflict, issuing a cease fire. Bracknell's remaining troops not being influenced by the Sith retreat under penalty of death(Saresh is mad xD) and this new government tries to wrestle with the idea that it was built specifically to commit genocide. With the resistance not needed, most of the allies disperse, allowing Yerbol and Aria to spend time alone(He MIGHT profess a desire to be together then...don't know yet, but the way they're bonding, it'll probably happen) and lick their wounds before heeding a call from the Masters later in time(Three months? I don't know, but some time off would be nice for the two of them xD) 

What do you think?