Star Wars Universe Questions

I have a few questions about the SW universe and this can apply to cannon or just reading between the lines.

1. How are the governments for the galaxy structured? I am assuming that a planet is a stand in for an individual country. Does each planet have its own government. Or are they structured like a confederacy, like the EU (before Brexit).

2. Is there a common currency across the galaxy? And how are financial affairs structured? Is there a single bank?

3. How about the military and police forces? Is there a single one for a planet? Or is there a national police . Followed by an army.

4. How about the courts and law. For example how are disputes handled between parties on different planets.

5. With regard to the TROS and Rey's ending. Presumably it's theorized that she'll he starting a new school. Would that be on existing property or would she have to build one? I guess also tying into this, even though she rejected the Palplatine name. She still is his only surviving relative. Would that mean that she inherits an of his surviving estate?

6. The Sith are supposed to be gone and destroyed. But would that negate others from practicing or studying the dark side of the Force and how to use it to obtain power?

7. Is one always a Jedi? I mean are the Jedi's like Catholic Priests/nuns. They might study study and join the order. But later on move into something else? Such as maybe joining a police force, the military or becoming a bodyguard for the rich.

8. Are the Jedi the only ones who use lightsabers. Or can anyone with the means acquire one?

That's all I can think of for now. Thanks in advance for any insight.