Re: Laanat, Curse !
I can never doubt Allah being Raheem o Kareem, but I don’t believe sayings which state huge rewards and big azaab for small deeds (who over quoted them). For me Islam emphasizes on actions and its this passive school of thoughts that is responsible for major damage to Islam.
When Quran says at many places for example Surah Ankaboot’s first ayat that no one gets place in Jannat unless he/she and his actions are examined , then what is the need for such duas. If Islam has to give such importance to these kinds of Duas then what was the need for ayats in Quran related to Jehad, Haj and other duties. It should have taught 'go to a corner, read this and that dua and you will get all rewards hereafter.
Offcourse, There are some conditions for Qabooliat (acceptantce) of ibadaat. Anyway we r going way off the topic. The reference of Dua-e-Sanam-e-Quraish was given t answer one of your questions.