There is nothing in the Quran or the Sunnah to indicate that Prophet Muhammad can hear every Du`a or call from human beings. Rather it is proven that the only thing that reaches the Prophet is the blessings and Salams of those who send blessings and Salams upon him.

Ahl Al-Bayt are the members of the household of the Prophet (peace and blessings be upon him). Allah has bestowed upon the Ahl Al-Bayt of the Prophet numerous virtues. There is no intercession specifically for the family of the Prophet (peace and blessings of Allah be upon him).

Praying to the occupant of the grave is major shirk. Praying the funeral prayer at the graveside is permissible. Praying the funeral prayer in the graveyard is permissible. Praying towards the graveyard is haram according to the correct opinion.

The greatest intercession is al-maqam al-mahmud, which the earlier and later generations will ask the Prophet to intercede for them with their Lord so that He might relieve them of the horrors of the Day of Judgement.