If the Muslim prays Witr then he wants to pray Qiyam Al-layl after that, he should pray them two by two, and he does not have to repeat Witr.

There is nothing wrong with delaying `Isha’ prayer in Ramadan on condition that the Imam does not delay the prayer so much that he causes hardship to the members of the congregation.

The one who prays eleven rak’ahs is doing well and is following the Sunnah. Whoever makes the recitation shorter and increases the number of rak’ahs is also doing well. For more, please see the detailed answer.

Qunut is the name of a du’a (supplication) offered during prayer at a specific point while standing. Qunut is recommended in witr prayer and when a calamity befalls Muslims. For more, see the detailed answer.