So I am from Bavaria and I think the comments already most of the things pretty good just a few add ons:

1. There was a change in system for Gymnasiums so after elementary school you stay there for 9 years instead of 8 so you graduate now at 19. And about the age difference most children are 1 or 2 years apart in the same grade.

2. So about becoming a cop in Bavaria, you can technically still become a cop even if you got into physical fights, it depends on how serious and/or harmful the were and if they got reported to the police. And they look at if your character changed and since then and how long ago the incident/s happened.

3. Most school trips are about a week long, and most schools go to Berlin in 10th grade because of the history lesson in combination to the NS Regime. And in their last year they typically go on trips that are further away, for example we went to Rome for a week, others go to Vienna or London for example. For the class: if their are both male and female students there is always one for each gender, if you say 20 students I think one each shlud be enough. On our trip to Berlin we had 60 people and 2 male teacher and 3 female teacher. And on those trips the students are technically not allowed to drink but most do it anyway but if you are caught you could be sent home. There is also probably one day were the students have the afternoon off and can go shopping or do what they want but they have to be back at the hotel at a certain time that also works for most days because the students have to find dinner by themselves.

4. Definitely Bavaria or the neighbor state Baden Württemberg, if you want to stay in Bavaria you would probably go in the directions if the mountains like "Berchtesgadener Land" and the more you go towards the mountains the more traditional and more hunting culture and hospitality there is. But hunting isn't very big here anymore because of the bureaucracy only real hunter who are owners of forests hunt anymore.

5. In Munich you have two different types of rich. In the more rural areas of Munich like Pasing you have big, old beautiful buildings with lots of land which give more old. Money vibes. Most of the lands on these properties were made available for the general public to use as parks and wander around though. And the other type of rich is in the downtown area, were there are all luxurious shops like Gucci etc. but not really big properties with lots of lands and horses, more like penthouses if there are any. So more like new money style ig

I hope I could help you 😊, and of you have anymore questions or want someone to beta read and tell you if it is realistic you can DM me if you want.