All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad, sallallaahu 'alyhi wa sallam, is His slave and Messenger.
The statements that you mentioned in your question violate the Sharee’ah (Islamic law) to different extents. The first statement refers to the Prophet, sallallaahu ‘alayhi wa sallam, who is the grandfather of Al-Hasanayn (Al-Hasan and Al-Husayn ), and it is meant to seek his help; in other words, addressing supplication to someone else other than Allaah The Almighty to ask for something that cannot be granted except by Him. The person who does this is committing Shirk (polytheism) in worship, because supplication is worship, as stated by the Prophet, sallallaahu ‘alayhi wa sallam, who, after saying that, recited the verse (which means): {And your Lord says, "Call upon Me; I will respond to you." Indeed, those who disdain My worship will enter Hell [rendered] contemptible.} [Quran 40:60] [Ahmad and Abu Daawood] [Al-Albaani: Saheeh] Supplicating in this way is impermissible, even if it is the Prophet, sallallaahu ‘alayhi wa sallam, whose help is sought. This is because he was a human being and no human being can bring about benefit or harm to themselves unless Allaah The Almighty wills.
The Prophet, sallallaahu ‘alayhi wa sallam, was a human being favored with the message of Allaah The Almighty and with Prophethood. Allaah The Exalted Says (what means):
· {Say, "I am only a man like you…} [Quran 18:110]
· {Say, "I hold not for myself [the power of] benefit or harm, except what Allaah has willed.} [Quran 7:188]
The second statement is also wrong because, as far as we are aware, the Prophet, sallallaahu ‘alayhi wa sallam, does not attend any of the gatherings of the living. It has not been reported that this happened with his Companions, who were the best slaves of Allaah The Almighty. Some ignorant people leave an empty chair or mat in their assembly for the Prophet, sallallaahu ‘alayhi wa sallam, to sit on. This only indicates their complete ignorance of Islam and its Sharee‘ah.
The last three statements all refer to making Tawassul (intercession) through the Prophet, sallallaahu ‘alayhi wa sallam, which is a religious innovation that only appeared after the era of the Companions and their two successive generations. Al-Haafith ibn Ahmad Al-Hakami mentioned in his poem that none of the Companions nor those who followed them in piety ever did that.
Please note that claiming that the one who does not take the Prophet, sallallaahu ‘alayhi wa sallam, as an intermediary in supplicating Allaah The Almighty is a loser discredits the righteous predecessors who never did that and never called people to do it. Actually, if there had been any goodness in this, they would have been the first to do it.
Allaah Knows best.