How sound is the virtue associated with certain ذكر (remembrance of God) such as reciting prayers upon the Prophet (peace and blessings be upon him) 1000 times a day (emancipation from Hellfire)?

Remembrance of Allah and sending prayers upon the Prophet are among the best acts of drawing closer to Allah. As for the hadith: "Whoever sends prayers upon me a thousand times in a day will not die until he sees his seat in Paradise," it is very weak (da'if jiddan), and its narration is "munkar" (denounced). The reason for its weakening is the disagreement among scholars regarding one of its narrators.