First, regarding saying ‘ameen’ behind the Imam in the prayer, if it is in the Witr prayer or in Tahajjud or this type of prayer, then there is nothing wrong with this. And you can continue doing this as it is permissible for you to say ‘Ameen’ behind the Imam. This is to happen when the one who prays hears the Imam say a du’aa preceeded with such as ‘Allaahumma…’ [or 'Rabbaana']. However, when the Imam is glorifying Allaah ‘Azza wa Jal, then you do not say ‘Ameen;’ rather you remain quiet.If however the Imam makes du’aa in a morning prayer, then you do not say ‘Ameen,’ as this is an innovation.Secondly, regarding raising the hands during the Qunut, if this happens during a Qunut in Fajr, then you should not raise your hands – this is an innovation, although the prayer still remains correct but you shouldn’t raise your hands eventhough your Imam persists in saying these supplications. …Thirdly regarding the extra supplications in the Qunut as in known in the Qunut of Hassan bin ‘Ali (radhi Allaahu ‘anhumma) that was taught to him by the Prophet sallallahu ‘alayhi wa sallam himself; then this Qunut is a brief supplication. I personally do not consider it permissible to add to this Qunut and elongate it with extra supplication due to it opposing the Sunnah of statement in which the Prophet sallallaahu ‘alayhi wa sallam taught his grand-son, Hassan.Additionally, this extra wording contains false praise which innovates in the supplication and causes hardship to those who pray behind the Imam; you even find that the Imams who do this often recite this in a melody such as singing, and reciting in a beautiful voice should only be done when reciting the Qur`aan.
Your Reminder Fatima who love you all for the sake of Allah