In a private block you can have a party and play loud music until 10pm on Friday nights, and midnight on Saturday. With normal music, not a live band.
If loudspeakers are used for electronic music then you need a permit.
I only say that because we had a garden party with a live band using "plugged-in" loudspeakers and therefore needed Gemeinde/Police permit with a restricted time limit for the noise.
Actually we had the party and only found out about the permission after
the event (the house owner has a good relationship with his neighbors)
But was warned about any future events.
I don`t envy you having to have "door control" security! But necessary I guess. Just get the biggest and most muscular guys to do that, on a rotation basis? Preferably those with shaved heads.