A few words I'm not sure should be modernized:
Gehennum -> Gehenna: They both refer to the same concept, but I'm not sure if it is an actual sound-like word.
Kurbâj -> 
Kurbash: Present in 
MW, but I'm also not sure if the sound is similar enough.
 
Ma sh' Allah -> 
Mashallah: Not present in MW, but in 
Wikpedia. Also, 
Inshallah is constructed similarly and is present in MW, and it would make things more consistent if both were modernized.
 
Also, two more questions, both regarding chapter 15:
There is, in 
page 125, a letter, which has a ℅ character, which I believe is an abbreviation for "care of", should I change it to use 
c. o., with appropriate semantics?
In the footer of the letter the sender is on the left side, center-aligned with the rest of the letter, with a bracket dividing them. I don't see any point in keeping any of this formatting, and think "Mary" should be before "Madame" with an added comma (editorial). What do you think?
Other than that, there quite a few words with strange spelling, but I'll change the ones I can find in MW.
--Hendrik