I tend to agree with the flag policy on city owned land/buildings - these should be secular and not favor any one group. However, it would not be out of line to fly flags relative to a day or month, like say "Arbor Day" or "Black History Month" (don't have a clue about or if these flags exist). As for the adhan, the city should not favor it over any Church bell ringing or similar, nor should any religious "noise making" have any preferential treatment over other religions or businesses. Basically, a city should establish fair noise ordinances and those should apply to all - equally.