I'm from Switzerland and live in Germany and I think it is very relaxed. Too relaxed for my liking to be honest. Sometimes the bins are still out in the evening??? What kind of anarchy is this ;-)

Really, it's just what you are accustomed with.

Stores closing on Sunday is a good thing I think, it makes it easier for families to have a day together and kind of resets the week. On Saturdays they are also open until 8pm, some even until 10pm or so.

>I remember once I waved at my neighbours who were sitting eating in a common garden area and they acted super confused that I would wave to them.

You need to yell "Moin" very loudly. If you are in Southern Germany, you need to yell "MOIN" twice as loud to establish dominance.