Regarding the mosque -- There was a mosque in Morocco that served as the site for a clue box; no tasks were performed there but the Racers did not enter the Mosque itself, just the outer courtyard. Both male and female Racers had to make sure they were respectfully dressed (head scarfs for the women as I recall) for that locale.
If a mosque turns up again as a place the Racers are directed to, I doubt it will be anything more that a clue box for a route marker clue.