The "doubled E" issue has been clearly answered already; this answer is to add some thoughts regarding the "low G" issue.
In the answer you link to, the author indicates that it also may be an editorial addition. That is, based on one or more sources, the editor may suspect that the low G was (erroneously) omitted in (some of the) existing scores, thus creating uncertainty as to the composer's intentions.
There is good reason to suspect this, as the G-moment is a rhythmically strong moment and at the conclusion of the left hand's scalar passage. It makes musical sense to continue the octaves to that point rather than abruptly shifting to a different texture.
The effect of the texture shift, however, is worth considering. If you keep the low G, then the musical emphasis tends to be on the left hand scale; whereas, by leaving it out, there is an abrupt aural shift from the left hand to the right hand. There is an aesthetic decision for you to make in this case.