My question is how often do you get ship/cantina quests from your companions? On my level 30 Trooper, I've had roughly five each from both Aric and Elara, but on my level 19 Sith Warrior, I've had only one from Vette. Is it tied to story, affection gain, or both, or what?
Both; affection value and current story level. Some companions can't/won't talk with you any further until you see a certain specific story arch because their next convo with you may entail discussing that particular spoiler. So it is possible gain affectiion so fast that your convo's with them are 'put on hold' for a lack of a better term. Once you finish chapter I, II or what have you, they will have a bunch of convo's that you can access all at once in succession.
As far as info goes, searching in the class forums here helps though it can be tough to navigate if they don't title their threads with specific buzz words so you know exactly what the topic is about. Other than that, I never played WoW but I imagine their Wiki is more extensive because of how long the game has been out for. I'm sure in due time, and with the help of volunteers, the SWTOR Wiki will have more info added to it as well.