1) What meaning we meant by Curse is different what Islam says. Curse is Dua ( supplication) but for against the person and not in his/her favor. So curse means May Allah keep away him from His Mercy. Therefore if he deserves for this curse Allah will listen from those who is the oppressed one.
2) Yes there is Luck but again I want say not in that meaning which commonly people use in their talking. Allah has set for everybody 2 destinies one is final and without having any change. But the other one can be changed by everyone with his/ her own efforts and struggle. So if anyone does any positive thing he will be a fortunate person but those who are lazy will be unfortunate. Now you can say it good or bad luck but actually luck is not good or bad it’s our own actions and efforts and work is good or bad which make our destiny good or Bad.
3) 6th Imam hazar Imam Sadiq (a.s) has said Beware about you amal because our intercession would not be in Barzakh so yes there will not be shifa’at in Burzakh but yes it would be on the Day of Qiyamat with condition. Not for everyone who says I’m follower of Aimmah.