Like most other European cities, tipping is not required but appreciated. A "service tax" is added to most restaurant bills but feel free to leave a few extra coins if you get great service.
Before you start saying "not another church," hush. Check out the St. Clement Basilica, which is a church built over a church built over another church. Explore this 3-tiered structure just steps from the Colosseum, and see how modern Romans to early Christians used the space.