I had a couple of questions: (1) When does puberty for male start? (2) How do I make up for my Qadha prayers? (3) How can I strengten my iman? (4) How can I avoid Satan during namaaz?

A brother told me that we must recite the last three Surah of the Quran: Ikhlas, Falaq, Nas in the 3th rakat of Witr. Does this has a origin? (2) Also this brother told me that after the Takbir for qunut in the 3th rakat of Witr we must not fold hands but raise them like in duaa and leave them them like that for the duration of the qunut dua. He told me that this was related from Abu Hanifa by his student Abu Yusuf (recorded in Haskafi, Ibn Abidin) Is this true?