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.

Intercession in Islam means mediating for someone else to gain some benefit or ward off some harm. Intercession in Islam is of two types: 1- intercession that will take place in the Hereafter, 2- intercession concerning matters of this world.