Salam Brother Student
Your questions will be in blue and my answer to them will be in black.
Jews and Christians are to believe that Quran is divinely inspired and is from the same God 1. What happens if whoever (or however many) among them doesn't do so?Are you asking me what is going to happen if they do not follow God's orders? God only can give you a detailed answer for this question but as far as I know from scripture, if you do not follow God's commands you have to answer for it,and your fate is generally thought to be unfavorable.
2. Where does Quran place them or calls them? If, they are not following God's orders they are not following God's orders, why does there have to be a label for them? There are Muslims who do not follow all the commandments, is there a different label for them? Then why one for similar Jews and Christians? Generally, they are people who do not fear God enough, it is that simple, no label required.
3. Did Sir Joseph Islam provide link to resources/evidence where some/any sect from the Jews/Christians uphold this theology? Not that I am aware of. But, just because people of the book are not doing what the Quran asks them to do, doesn't mean the commandments do not apply. These people are not doing what God asks them to do, just like Muslims who are making hadith as an indispensable source of law along with the Quran. The presence or absence of a sect in this case is inconsequential.
4. What do this Quran believing BUT Torah/Gospel following sect of the Jews/Christians calls or treat those among them who don't?Again are you looking for a label? How does it matter what they call each other? What is of importance is the alignment of their belief system with that of scripture. God chose to call all those who believe and submit to Him as Muslims. Prophet Jesus and Moses are called Muslim in the Quran. What other labels are you looking for?
5. In other words, is there any evidence or traces of two major sects/groups among the people of the book disputing and debating this belief/thought?Not that I am aware of. Most Muslims are unaware of the true message of the Quran, are you asking me that, are there Christians and Jews who are aware of the true message of the Quran and are debating among themselves, when majority Muslims think that Jews and Christians are disbelievers? I highly doubt this.
6. Is there any Synagogue/Church that caters to this unique believers anywhere in the world?Are there mosques where Quran-centric people and their ideologies are openly considered as valid? very few to non-existent, but that does not mean our approach is wrong or that we do not exist. Just because there maybe no such Church or Synagogue, does not mean there are no believers of this kind. We exist, this should be evidence enough that maybe there exists such people from among Children of Israel. God knows best every person's heart and soul.
They are asked to read the Quran and refer to the Quran in order to understand which doctrines and laws became corrupted in their books1. Which sect among the people of the Book believe/uphold this theology?I am not aware of any sect doing this today. The Quran asks them to do this. If no sect is doing this today, does not mean, the Quran's commandment is lifted. If, they are not doing this knowingly, they will have to answer to God.
2. This assumes they must read/parse the entire Quran, then logically speaking how or why would they go back to something which is protect and 100% Truth to something that is NOT according to their own belief after confirming QuranThis is not an assumption, the Quran asks them to read it, and think over it. The Quran then asks them to go back to their own scriptures and follow them faithfully and sincerely. They would go back simply because God asks them to. Again The Quran mentions clearly the beliefs/laws/rites etc it is confirming. They are asked to use the Quran as a book to discern their beliefs and laws with. The Quran accepts that the Bible went through changes at the hands of humans, but yet, asks their adherents to come back to those beliefs that are confirmed in the Quran.
3. How can (after having believed Quran as Divine writ and to be from same God) they will oscillate between EXPLICIT & GRAPHIC (in Quran) and ALLEGORIC (at best in TORAH) on the Day of Reckoning and the Hereafter life?The Quran is the book confirming the Bible, not the other way around. They are asked to compare and correct their Biblical beliefs and rites with the Quran. The Quran confirms for them, the truth in their scripture. If the Bible differs from the Quran regarding a belief , they have to accept the word of the Quran because the Quran protects the Bible, not the other way around. The Quran is very clear when it is lifting or correcting a law for the Children of Israel, commenting on the nature of these laws, divine ( they can consume animal fat now) or made up by humans ( monasticism).
4. After reading Quran, are the Jews not required to correct their belief/doctrine (whilst keeping the Torah law in their life) in/about Prophet Isa AS?Yes, they are asked to correct their beliefs according to what the Quran proclaims.
5. After reading Quran, are the Christians not required to correct their belief/doctrine (whilst keeping the Torah law in their life) that there's no 2nd coming of the Prophet Isa AS?Please see my answer to your previous question.
6. If they fail to do so, where does Quran place/call them?They are simply not following God's orders knowingly, in that case they become disbelievers. But, the state of the heart and truth about one's soul is only known to God. So, I will refrain from labeling anyone, this is a completely personal decision on my part.
Here, are the links where Brother Joseph answered my questions :
http://quransmessage.com/forum/index.php?topic=849.msg3235#msg3235http://quransmessage.com/forum/index.php?topic=887.0