Hi there! Not the dev, but I've been playing for a while so while I cannot update the tutorial, I can answer your questions!
1. In 7-day mode, your goal is to make $50 by the end of the week to save the lighthouse. In endless mode, just make as much money as you can and don't go bankrupt lol.
2. Doesn't matter how you apply stamps, as long as the value adds up. I personally like laying them out super neat, but that's just my perfectionism speaking.
3. The ships send automatically at the end of the day, no need to worry about it!
4. When you get updates for your notebook, just drag the note announcing the update onto the book. It updates automatically.
I'm not sure what your native language is (not like I'm fluent in anything but English anyhow), but I hope that I was able to help with my answers. :)