Hi!
1. Not sure, since we only have download links leading to our site, so that's maybe why Itch can't update the game. But that's the distribution system we had for 2+ years here on Itch.
2. Sitara will get a story continuation in the first half of next year if everything goes according to plan.
3. Seraphine will come before Sitara, so you will see how it plays out yourself. With her we really wanted to go with a detective theme and will continue on that theme in the next chapter!