1) It is not haraam to turn the ring during the qunoot however it is not proven to be from one of the mustahab acts of Qunut or prayer. It can be done with the intention of raja’ almatloobiya, meaning you hope for it to be accepted.
2) Yes you can say bismillah, or recite anything however the purpose of Qunut is to ask God. If a sura or aya consists of dua that is better to recite.
3) The qunoot is not Wajib.
4) It can be said in a different language. However it is best to say a few words of Arabic first like reciting salawat then ask Allah in a different language to gain the thawab of the qunoot.