Don't let the door hit you on the way out!

Everything you said is true. But these rules apply to everyone here and people are pretty strict about rules and customs here in germany. And we really like having our peace and quiet. This can be seen as really cold and strict if you’re not used to it. But that’s why everything’s working here and why it’s so peaceful and safe here. Don’t take it personal, you seem like a nice guy. But if you want to live here, try to abide by the rules and customs. That’s how it is here. “When in Rome, do as the romans” I can understand that neighbor saying you’re too loud, maybe she was right, idk, but “walking too loud” is silly. There are definitely people that overdo it with quietness.

If you put your shoes on a seat or you are talking so loud as if you're alone in public transport, I will call you out. But I would not call the police on anyone because of their behaviour. I believe there is a difference between a huge city and smaller areas.

Dare to cross the road other than at a designated crossing and old women go mad!

It could be they don't want you there, and think you are wrecking their two thousand years culture, and that's why they enforce the rules.