Witr and Nawaafil

Witr Salaah

Q: I prayed witr salaah with three rakaats. Meaning, my witr is similar to magrib salaah but with a Surah and then duaa qunoot in the third rakaat. Is this the correct way of reading witr salaah?

Sunnats after zuhr

Q: I started praying the 12 Sunnahs prayer. However, I want to pray four rakats after Dhur and not two because four is recommended. Are the four rakats after Dhur with two tasleems like the four rakats before Dhur?