Is it permissible to seek blessings from graves or from those who tend to them? Is it true that the blessing of a shrine is more important than obligatory prayers? And should one heed the words of the shrine's attendant regarding the suitability of a location for a commercial project?

Summary of the answer: One should adhere to the Sharia and reason in combating superstitions and attachment to the deceased, for Allah alone is the Giver and the Withholder, and seeking blessings from other than Him is polytheism. Islam has fought these illusions and commanded us to rely solely on Allah. The dead possess no power to benefit or harm, in accordance with the Almighty's saying: (Say, "O mankind, if you are in doubt about my religion, then I do not worship those whom you worship other than Allah, but I worship Allah who causes your death; and I have been commanded to be of the believers." And [commanded], "Direct your face toward the religion, inclining to truth, and never be of those who associate others with Allah." And do not invoke other than Allah that which neither benefits you nor harms you, for if you did, then you would be of the wrongdoers." And if Allah should touch you with adversity, there is no remover of it except Him; and if He intends for you good, then there is no repeller of His bounty. He causes it to reach whom He wills of His servants. And He is the Forgiving, the Merciful. Say, "O mankind, the truth has come to you from your Lord. So whoever is guided is only guided for [the benefit of] his soul, and whoever errs only errs against it. And I am not over you a guardian." And follow what is revealed to you, and be patient until Allah judges. And He is the best of judges.) (Yunus/104-109), and (And those whom they invoke other than Allah create nothing, and they [themselves] are created. They are dead, not alive, and they do not perceive when they will be resurrected.) (An-Nahl/20-21).

It is not permissible to intentionally visit graves to supplicate there seeking blessings, for this has not been legislated by Allah or His Messenger, nor was it practiced by the Companions or the Tabi'un. Sheikh Al-Islam Ibn Taymiyyah says: "That one should intend to supplicate at [graves] feeling that supplication there is more likely to be answered than elsewhere – this type is prohibited, either as a prohibition of unlawfulness or as a prohibition of disdain, and it is closer to unlawfulness." This is because it is a means to polytheism, and because Allah has not permitted it; whoever legislates it has legislated in religion that which Allah has not authorized.