Salaam Shaunee,
Your questions were
does the Quran in some way replace all scriptures before it? I was told on another site that the Quran is sufficient enough, and that Muslims do not go by any other book..... but isn't it somewhere in the Quran where it is said that these books were sent down to the prophets beforehand? What is the statis of the ancient scriptures, and how or why does the Quran superceed them?
The reason I ask is because..... it seems to me that by rejecting any and all scriptures besides Quran, and focusing on only one prophet would seem like all the other prophets and scriptures are worthless in some way. I can't see how that could be.
I don't know if you already read Quran, but if you do, you'll realize that the most important biblical themes are told again, sometimes with rectifications, like Jesus-Issa being not the Gods son, but a prophet like the other prophets. Also rectification of the adultery punishment...
Also, if you read the sura "the prophets" you'll see that in quran we are supposed to accept and respect all the prophets of God, they were all bearers of the same message, which has been reiterated only because we humans changed it's sense and perverted it.
"Traditionnal" muslims or I'd rather say sunnis actually do focus on the prophet, but what we try to do here is to focus on the message and to recover it's primary sense.
I'm sure that, may be Marie, may be someone else with a quran browser and/or a better memory than I , will be able to give you the relevant verses!
Elke