This chapter was translated slightly differently than before. Specifically the line where Delin mentions that the attackers are nearly on par with the top 100 was worded more clearly. I'm guessing the reuploads are all just retranslations.
If I recall correctly, he fired from low to the ground, and in fact the reason he didn't use a scope was so the silhouette of his gun would be smaller and less visible to enemies
I don't think he knows how or is even able to achieve the ending he wants without Yoo. If Yoo is dead, then there is no way Dokja will be able to succeed in the subsequent scenarios