(Unless she is unaware that he is a droid... the Kaggath only states that they are aware of each other, not that they know each other's secrets. GOTO was quite protective of his actual identity, masquerading as a human Exchange member)
Now, what are GOTO's vulnerabilities? He himself possesses very little in the way of combat abilities.
His reliance on droids can backfire...
The question is, what would the best opening moves be for each side?
Unfortunately, for what reason I still do not fully understand, each and every Kaggath player knows that G0-T0 is adroid, as per K-canon. No idea why, it just.... is.
G0-T0 is actually very skilled in combat. In KOTOR 2 he was my favorite companion (Surprise, right?) because of his extensive use of stealth, his ability to corrupt the droids of others, and his skill with demolitions and blaster pistols. G0-T0's stealth will allow him to avoid detection (for sure from Sith Assassins and Traya) and allow him to ambush other forces. G0-T0 can handle himself.
I don't think G0-T0 will be loosing control of his droids anytime soon. His yacht is the droid control ship, so I'm not even sure if it's possible to hack them while they're under its command. Also, G0-T0 was known for his hacking of droids, he's an expert of it, even able to corrupt them in person. I doubt Traya will have a better slicer than G0-T0. Actually, we have no idea if Traya uses such things as cyber-warfare, and if she does, it's probably safe to assume that her hackers/slicers are sub-par to G0-T0 and his securities.
I think the openning move for G0-T0 would be..... well, okay, realistically, it would be to gather his forces. Move his HK-50s, buy some Vornskr, gather the Gand nest, etc. But the action starts when G0-T0 invades Malachor. You're right, Traya will underestimate G0-T0, she did in KOTOR 2. Thus making G0-T0 the aggressor, seeing as Traya probably assumes she is safe on her mega-fortress.