What I really want to say here is "why ask me? I didn't make this up? You can find this info anywhere." But I won't.
I hate long replies...I hate reading them and I hate writing them. But since you asked....
First of all, this short list should be easy enough for anyone to do the research for themselves. They aren't controversial view. They are mainstream, middle of the road, what you would find in the average commentary anyone can purchase at a bookstore. That's one of the reasons for presenting this information, to illustrate how even once we leave the Watchtower we often take for granted the lack of ability we have ourselves to do the homework.
But, to help you along, let me take you back one step further regarding you question about "empirical data" and the author of Matthew.
The empricial data and the conclusions have been developed via the application of textual source criticism. From this we learn that the gospel we call Matthew was NOT directly written by the apostle Matthew jimself. By comparing texts and textual witnesses of the Church Fathers, it is easy to see that the gospel did not have a title to begin with. The "According to Matthew" seems to have been generally understood since its composition, likely developed from the oral teachings of Matthew himself, but not from anything he literally wrote.
The techniques used to come to this conclusion are quite complex but nonetheless easy to study. For example, Richard A. Burridge, Dean of King's College London, where he is also Professor of Biblical Interpretation, explains what “critical” theory is in the Zondervan Handbook of the Bible and how it is a useful tool in helping us understand how the Biblical texts came about. By using techniques which fall under the approach known as “source criticism,” Burridge explains the popular Quelle source theory and how this has been used to explain the similarities and differences found in the synoptic gospels. You will find other like guides from Oxford, Collegeville, and even on Wikipedia that the Q-source theory has been the dominate view in academia among Catholics and Protestants alike. While not universal among everyone, the majority of the translators of the New Revised Standard Version, the Common English Bible, and the New American Bible Revised Edition, which include over 150 scholars from various denominational backgrounds, representing all major universities, subscribe to the conclusions of the Q-source as reliable theory. The list of these scholars is available from the publishers of these works, most of which have the information online, including the background of each and every person on their translation and editorial boards which will lead you to the information I presented. This will give you the scholars names you seek.
Why abandon the hypothesis of Q? This is new and is happening now. You will have to look up some of the current translation journals or keep in close contact with several of the universities and translation societies (even groups like ICEL) to stay on top of the latest in scholarship views. Even Wikipedia sources are behind by about 5 years or so (and that is when they are accurate--as many can tell you that some of the time, due to anyone being able to add or change things, they are not). The traditional view that Mark wrote his gospel directly from Peter's personal account has become easier to verify over the years. As manuscripts keep being discovered, we learn how to more accurately translate and understand what the ancient writers meant when they used certain terms. Some of the materials previously thought to cast doubt on Mark's source for his gospel appear to have been read incorrectly, and this has given a boost to the traditional view that Mark wrote his gospel later than Matthew's.
While Q is still the favored theory, it is no longer taught as the dominant one. The reason? We have written testimony from several ancient witnesses among the Fathers that support the traditional view, but no one has ever discovered Q. It does not exist, and no one mentions it in any of the Fathers.
But Q is not being abandoned. How you got that out of my writing that the theory is not weighty enough to counter the support we have from the testimony of the Fathers is beyond me. Perhaps it is because you may not be aware that in some circles there was opinion that the Church Fathers were wrong or we were reading their comments incorrectly. Now we know that their reading and testimony is correct, and this means that Q is no longer a strong enough theory to reject the traditional written testimony of the Fathers.
As for point 2, this is very old news. It demonstrates how dark the recesses of the Watchtower are if we have never heard of it. For example, since the 1960s several scholars have helped unravel the "Jamnia" mystery. When the Qumran (Dead Sea Scrolls) were discovered, all of the deuterocanonical works found in Catholic Bibles (which JWs and some Protestants refer to as "Apocrypha") were found among them, and all of them written in Hebrew-Aramaic. This was the total opposite of the stories associated with the Council of Jamnia which said that the Jews rejected these works because 'none of them were originally written in Hebrew.' Since Qumran (Dead Sea Scrolls), more of these deuterocanonical texts in Hebrew have been found. We now have all of them, except for the Greek additions to Esther, which, according to the stories surround Jamnia, we should not.
About 15 or so years after this discovery several scholars, Jack Lewis being one of the foremost, traced the Jamnia stories to uncover that the "idea" of such a "council" was a hypothesis, much like Quelle, and not historical. Over the years anti-Catholic groups added stories to discredit the "additional" books found in Roman Catholic translations, and some anti-religious groups picked them up and repeated them from there, not checking their source. After hearing the same stories from practically everyone, no one thought any different until the discoveries of these Hebrew versions of these books. So we now had evidence that suggested something was wrong about the Jamnia story. After much investigation we now know what I am writing to you about (I didn't invent it).
The Anchor Bible Dictionary, published in 1992, has Lewis stating on pages 634, 636-637:
The concept of the Council of Jamnia is an hypothesis to explain the canonization of the Writings (the third division of the Hebrew Bible) resulting in the closing of the Hebrew canon. ... These ongoing debates suggest the paucity of evidence on which the hypothesis of the Council of Jamnia rests and raise the question whether it has not served its usefulness and should be relegated to the limbo of unestablished hypotheses. It should not be allowed to be considered a consensus established by mere repetition of assertion.
The origins of the Jamnia theory go back to Heinrich Graetz, who created a theory based on his interpretation of Talmudic and some Misnaich Jewish sources. With the discovery of the Hebrew texts of the so-called "Apocryphal" books of the Old Testament, the Graetz theory can no longer be sustained.
On the same basis, the Quelle theory may lose ground because new light on extra-Biblical writings and their meanings has given more weight to the traditional dating of Matthew and the likelihood that Mark was not a source for either Matthew or Luke. One cannot read portions of Quelle because Quelle is just a theory. There has never been a Quelle to read from or discovered while we do have these extra-Biblical authorities.. It is just a way to explain similarities in the synoptic accounts that cannot be explained otherwise by the critical approach.
You will have to do the homework on this--which is why I am trying to get people to do. Instead of challenging me, you should challenge yourself to make sure that what you think you know is true can stand up to what you discover from others, and that your means of education can stand the test of critical analysis from independent sources. Instead of doing Internet searches, go and find these books I mention themselves. Contact the scholars whose names appear. If you can, write, call or better yet visit them face-to-face on their campus (if they are currently teaching or part of the education body). If you’ve yet to get a university education, go and get a degree or two. Learn various logical approaches.
In the end, we should never settle with our own feelings and conclusions on matters. We are likely to be wrong, especially if all we ever studied was Watchtower information. We should learn how to make critical and scholastic approaches of research and study become our own tools (and we can’t learn to do that alone or through the Internet alone—you will need to find others, hopefully those who don’t think like you so you have a good balance to keep you from sticking to your gut instead of the facts). Learning to think for ourselves often takes learning how to do this from those who do, and that means going to those outside the Watchtower. Don’t do it alone, and don’t do it with just fellow ex-JWs. Do it where there are real ways to ensure that even your own bias doesn’t get the better of you.