Some questions on the walls, religious and cultural victories. (Sid Meier's Civilization 6)

There were some issues when playing:

1) somehow lost the ability to build walls after the first three cities, although opponents have a lot of them. In the 5th part was in each city to build. In 6th I was not paying attention, maybe it was okay. But in the last game for some reason, only in 3 towns out. The only thing that came to mind - cities on different continents. Map of archipelagos. Although 3 cities on one island failed to make the same wall.

2) Until now, the end can not enter the religious victory. It is clear that the religion should be spread, but how can it be strengthened? Again, in the last game for some reason I even found I couldn't. The maximum number of opponents was. There is a certain number of religions, and I do not have time on hand? :)

3) cultural victory as a whole is clear, but you do not observe the same facilities as it was in the 5th part, when you saw how your culture is catching up or lagging behind the culture of the opponent. In the 6th same can only be judged by the total the icon and the level of tourism and culture. Although still not clearly. Especially surprised when I and culture and tourism are significantly higher than the level of the opponents, but at one point me on the right in the news crawled an icon that the culture of the opponent was in me to dominate, although its value is lower. In short, I'm perplexed. %)