Making dua through the waseelah of Nabi (Sallallahu Alayhi Wasallam)

Q: Can we make Dua with the Waseela of RasoolAllah (Sallallahu Alayhi Wasallam), the Prophets and the Auliya? Some people say that we should ask directly from Allah Ta’ala and not make dua with the Waseela of RasoolAllah (Sallallahu Alayhi Wasallam), the Prophets and the Auliya. Please provide reference from the Quran and Sunnah.

Getting married without the permission of one's father

Q: If I have married someone without my father's permission, is it valid? There were people who were present during the marriage but I don't know them. Hanafi mazhab allows it but in Tirmidhi, its against this type of marriage. Why is it? What should I do now if I got married like this without knowing. Should I get married with him again with my father's permission?