May Allah guide us all. These are the same pre Islamic misconceptions and superstitions. These are the same questions shaitaan wants a muslim to be indulged in.
A grave is another thing compared to a shrine. A shrine is made for the purpose of worship where people come to seek blessing, pray, supplicate and tie threads to some furniture etc etc.
What do you really mean? I am seriously confused. Allah couldnt solve their problems so they came to these siants. I believe you dont mean this but coming to a living person for duaa is a separate thing than to a dead person. Firstly your imaan and supplications should be sincere so Allah will surely answer without the need to ask another living person to pray for you. Sure you can ask more people to pray for you and there is nothing wrong. But asking a dead person for help is not proven by the prophet or the companions. Rather it is straight away termed as shirk by the ulama before and of our time.
Abu Bakr (may Allaah be pleased with him) said, in his speech after the Prophet (peace and blessings of Allaah be upon him) had died, “Whoever used to worship Muhammad, Muhammad has died, but whoever used to worship Allaah, Allaah is Alive and will never die.” (Narrated by al-Bukhaari).
This and similar evidence indicates that Muhammad (peace and blessings of Allaah be upon him) was a human being like all other human beings, who died as they die, and will never be immortal just as no one before him was immortal.
Whoever wants to put the Prophet beyond the human realm and claim that the Prophet is present in all places, is the one who should be asked to produce evidence (daleel). How does he know that the Prophet is omnipresent at all times? Moreover, those who make the same claim with regard to Allaah (should know that) this is kufr, deviation and misguidance. If this cannot be said for the prophet it cannot be said for anyone else. If someone dies his connection with this world is over until the day of judgement when you will be judged for your deeds.
The person who is asked should be capable such as one who is alive. It is not permissible to call upon the dead, as Allaah says (interpretation of the meaning):
“And those, whom you invoke or call upon instead of Him, own not even a Qitmeer (the thin membrane over the date stone).
If you invoke (or call upon) them, they hear not your call; and if (in case) they were to hear, they could not grant it (your request) to you [Faatir 35:13-14]