I am having a duscussion with some of my cousins regarding Quran and Shia creed. They are all sunnis (salafi). Their question is most of the sunni muslims follow the recitation of hafs narrated by Asim. The chain of narrators of the Quran are authenticated in Sunni books. But they could not found any authentication of these narrators in shia sources. As far as I know Hafs learned the quran recitation from Asim and Asim learned from Abdur Rahman Sulami who learned from Imam Ali (as) and they were all Shia narrators. But they are claiming that they were all Sunnis and Shias have taken quran from Sunnis. My questions-

1. We all know the Quran that is in our hand is in perfect form which was revealed to the prophet (sa). But what is the proof? How do Shias authenticate this?

2. Is there any different chain of narration of the Quran for Shias different than Sunnis?

3. Shias also follow the hafs qirat and this is the most pure qirat. But how do I prove to my brothers that the narrators were Shias? Is there any specific valid reference?