Side with Ruatai - Maia is their spy, Pallegina their enemy => Pallegina leaves; Also you're asked to kill the Huana leaders => guess Tekehu leaves?
Side with VaIlian trading Company - Pallegina is their bodyguard, Maia works for the opposing faction => Maia leaves
Side with the Huana - gotta blow up the Ruatai powder**** same as VTC => Suppose Maia leaves as well
Side with the Principi - nobody leaves, you take the Ghostship and fight the Huana leaders on Ukuzi or what's it called
Side with nobody - buy a ship, give it the dragon wing sail and the most expensive hull upgrade thing and just sail north when you're main-quest-stage is to follow Eothas to Ukuzi --> nobody leaves