I imagine a lot of us who do translation stuff were originally motivated by the desire to read a manga that had no translation. Anyway, this is an excellent translation. Almost every line is idiomatic and grammatically correct, which is far more than you can say for many things uploaded to this site.
As for the note on page 5, though, I will say that if somebody is reading this manga on this site, then chances are they already understand that whole ritual. You can put pretty much anything you want there, and people will understand.