Is there anything that the Dead Sea Scrolls made clearer regarding the texts of the Old Testament? Did their discovery change the way we view the development of the Tanakh?
They also show us that the canon was settled long before Jamnia. In the scrolls, we have at least partial copies of every book in the Old Testament except Esther. We also have many scrolls that are not canonical, however, even that teaches us something. Their literature can be broken down into three types. (The percentages are from my seminary notes with Dr. Waverly Nunnally who studied at Hebrew University in Jerusalem and Hebrew Union in Cinncinatti. His dissertation was on the use of Abba in the Dead Sea Scrolls, and he and his best friend wrote a computer program to reconstruct the scrolls from a concordance before their public release.)
The Essenes wrote a style of commentary called Pesher. All such Pesher falls into category 3. There are three ways that they show us the Old Testament was settled before Jamnia.
I think I may be posting an answer not quite in-line with what you were hoping for but I am not sure if anyone has published the various differences between the manuscripts that could answer your question properly. I apologize about that.
However, I think it might be worth mentioning that the main benefit of the Dead Sea Scrolls is not small clarifications here and there but that they provide a very large portion of the Old Testament scriptures that are older than those previously extant without 'hardly any difference'.
The scrolls are many:
The scrolls show how well the scriptures have been preserved to us today without any difference: