I was thinking the same thing as @avflinsch and then remembered that @viveke was an international student and perhaps the Professor (due to different cultural norms) thought that the hyperbole was actually useful. I had to help a friend edit a LOR she received and noticed that there were many hyperbolic statements as well. One of the letters was super religious and personal, going into detail not only about her family, but her inlaws as well! I think that ad comms may be surprised by such statements, but if it's coming from a non-native English speaker/ non-American, I think they'll be sophisticated enough to take into account cultural differences. I think that if I were you, I'd leave the hyperbole and awkward comments as is - if you edit it too much, the phrasing may end up sounding too much like your SOP.
The inaccurate comments about the classes and such I would fix, and if there's stuff he's left out, I'd add it and get his approval. Just be sure to thank him for his efforts and also trusting you with edits.
Good luck!!!!