ursus
why not include Bahai, Sikhs, Mormons, Hindu's, Parsis and Buddhists in your little thought experiment? why only set your limits at Islam? Is it because you share a certain sympathy for muslims that you don't do for mormons? why not ask the same question about christians and mormons and see how absurd that sounds...
Doubt is what makes me question and study all religions (inc. Islam) instead of accepting it blind folded, doubt is what makes me study christianity to understand it even more, instead of taking it blind folded...
why do you ask me to speculate about things that can't be true? that's like asking me "think outside the box! if a cat were a cow, could you milk it?" Islam doesn't have the benefit of doubt once you studied it....
to put it into extreme examples, would you take it so lightly if i asked you, what if the sect of Charles Manson really offered salvation equally with christianity? you can't compare an apple with a banana and call it the same merely because they are a fruit.