Imaya Kuroshka and Ilsa Zileti are lovers.Hence, first, Ilsa knowing that Imaya had rooms to rent; second, Ilsa telling Zorian not to raise the subject of marriage or husbands in Imaya's presence; and third, Ilsa's regular visits to the house. Given that this is a country where in many places girls are still not given a chance at a proper education and where marriages before the age of sixteen are not unheard of, it's probable that a teacher like Ilsa might not want it known that she bats for the other team.
Akoja has a crush on Zorian.The degree of her awkwardness in being assigned to go out with Zorian at the dance is easily explained by his remarks on the rumor-mongering nature of his classmates, but she consistently treats him as being something special (in her special perfectionist way) and, when he says that he didn't want to take a date to the dance in the first loop (because he hated formal events and would be a bad partner to whoever he took), she's hurt at the implication that he doesn't like her.
Jossed or Partially-Jossed
The missing watch is the key to the time loops.This would explain what the aranea matriarch was talking about as well as why the loop specifically starts at the time it does — presumably that's when the watch was lost.
Linked to the above: the original time traveler is the guy who owned the watch.This explains why the watch was lost in such close vicinity to the assault on the city — the time-traveler wanted to prevent the attack, and in the course of his attempts to do so, was separated from his secret weapon. Presumably the center of the loop was shifted to Zach by accident, and Zach continued repeating the loop for similar reasons to Zorian.