I see a problem with conflating the history of the Dead Sea Scrolls with that of the Septuagint. The two share the insertion of the word "light" in Isaiah 53.11. This could be explained by a shared tradition of reading an object into the sentence, in which none is provided in the Masoretic Text. In fact, it could be that the MT has a mistake in this verse. There isn't really a good reason for there not to be an object of the verb יראה there.
There is another place in which I think the Septuagint preserves a better reading than the Masoretic Text. Deuteronomy 32.8 in the MT reads "according to the number of the children of Israel" (לְמִסְפַּר בְּנֵי יִשְׂרָאֵל
, while the Septuagint reads "according to the number of the angels of God" (κατὰ ἀριθμὸν ἀγγέλων θεοῦ
. The
Biblia Hebraica Stuttgartensia suggests that the original may have been "according to the number of the sons of God (or the gods)" (לְמִסְפַּר בְּנֵי אֵל or לְמִסְפַּר בְּנֵי אֵלִים
, which would explain the "angels of God" in the Septuagint. I think that the Masoretic Text in this verse has been altered and a more original reading has been reserved in the Septuagint.
However, I oppose those who think that the Septuagint is somehow a better text than the Masoretic Text. The Masoretic Text has obviously been adjusted in some places - like Deuteronomy 32.8, but this doesn't mean that the rest of the text has been adjusted. Nor does it automatically follow from the fact that one text has a reading that you like in one verse (such as the insertion of the word "light" into Isaiah 53.11) that it is clearly the superior text either in this one verse that you like or in the rest of the text.
In fact, the history of the Septuagint confirms that it has gone through so much change and adjustment that we cannot even know what the word "Septuagint" refers to anymore.
P.S. Because of the footnote markers in the text that you've posted, I assume that this is a copy and paste job. You need to indicate the source for the text. Copy and paste is against the rules if you try to make it seem that what you've posted is your own words. I just found
this page, which contains a lot of the text that you pasted here. You need to indicate your sources and not steal from other people.