Agree with the comment above about ‘the glockenspiel thing” at Marienplatz - but if you are fit and energetic, climb the tower of St Peter’s across from the Rathaus (town hall). Small fee and tight staircase, but 360 degree view from top is excellent. And if you are on top when ...

Certainly not a problem using two passports. In fact immigration authorities in countries like AUS UK and US most lilely already know your dual status. And as already noted, always check in using passport you will show on arrival at destination. Where you pass through immigration on e...