I'd say no to Trip/Avy. They're too...weird for this setting. Having ancient eldritch bloodlines invites too much of a possibility of random ancient conspiracies and of one character's background dominating the story. I would rather have the characters forge their own paths. I mean, it might be interesting to have that around, but not if it drags everyone else into it. If Trip and Vincent have a duel to the death as representatives of Ra and Apophis, then I would like the option of ignoring them entirely as Alysis fights a duel to force some other student to return a library book.