Locke's father will appear somewhere along the way.Since Locke specifically mentions that he didn't die, he just left. It will also turn out that the father's name actually is Locke, and Locke did in fact name himself after him: at that point, Locke's real name will be revealed.
Sabetha is inspired by Diana Villiers.Crazy, witty, doesn't play by the rules, wears trousers, swears almost first thing we meet her, unusual coloring (red hair/black hair and blue eyes), good posture, fond of slightly dangerous physical activity (climbing on roofs/riding and driving), and has a habit of running off to foreign countries and leaving behind a celibate protagonist who is eventually reunited with her. In The Hundred Days Diana Villiers drowns when she drives a carriage off a bridge and in The Republic of Thieves Locke is told that Sabetha fell into a canal and drowned. Diana's even described as "gentlemanly."
Jean and Locke have contracted the nasty affliction known only as the CartwrightCurse.Well, as of the end of the second book, Jean has Ezri, while Locke has potentially two, since Nazca, while not truly a love interest, had a little Ship Tease going on between her and Locke at times, and, apparently, Sabetha may have drowned, though it seems very, very unlikely. This will add to just how unlucky and totally screwed the pair are. They just can't catch a break.
Locke ends up back in Camorr as Count of WestwatchOr as head of the Nightglass Company. I mean look at the title of Book 7!
The Eldren are Earth-menThe world is clearly another terrestrial planet with three moons, where a past civilization known as the Eldren left behind gigantic engineering works impossible to modify or duplicate, raising entire islands of a substance hard as diamond. Yet the world has humans, horses, dogs, cats and other Earth animals in human cities, while the wilderness host a dangerous and hardly known fauna. The humans had to get there from somewhere - the original civilization might have been an Earth colonizing mission which evolved over millenia first into an Empire and then in a quasi-feudal world after the breakup of the said Empire. Even the word "Therin" might have been a corruption of "Terrian".