Hi Aurora, I just thought I’d briefly address one of your questions.
“For the non-Jewish people who follow the seven Noachide laws, are they allowed to go further and take up some more of the Jewish obligations, for example keeping the Sabbath?”
Yes and no. There are a variety of views on this topic, but I think all agree that it’s inappropriate for Noahides to try to observe the Sabbath in all its many details. However, observing it generally as a day or rest and study and prayer is generally considered to be OK. Some rabbis encourage Noahides to take on Jewish observances beyond the Noahide laws, but I’m not sure which observances they have in mind. Keep in mind that although there are technically seven Noahide laws, each of these laws encompasses a number of more detailed rules. The Noahide movement has been growing a lot lately, and is becoming a full-fledged religion — they even have their own siddur now, which was designed by Orthodox rabbis.