The Hittite empire was certainly ephemeral, though, ranking in importance and obscurity with the Hurrian/Mitanni and the Lydians. It'd be nice to be able to dig more information up without the danger of being shot, but it doesn't look like that area's going to be stable enough for scholarly research for a very long time to come.
Velikovsky hardly ignores the El Amarna Letters. He devotes 114 out of 340 pages in his Ages in Chaos to the subject. His interpretation of them differs from the conventional interpretation because his chronology is different from the conventional chronology (which is the point of the book) This conventional chronology has the letters referring to a period when the Israelites were still supposed to be slaves in Egypt. As I understand it, Velikovsky thinks the they refer to the time when the Israelites were conquering Canaan, and says that much of the scholarship associated with the letters is an attempt to identify people and places that they refer to. But if the Habiru (of the letters) who threatened the land from east of the Jorden cannot be the Hebrews, then much of that scholarship is going to be in error if Velikovsy is correct about his redating of the history in that area.
ML/NJ