Is it okay to use the phrase grammar nazi to a jew
I don't think that's a proper phrase to use for anyone. Do you think he is critical of your grammar?
Yes, this word describes him very well
Even if you don't understand the hurtful connotations of that word, you shouldn't use it. That being said, you should probably educate yourself a bit more on the history of the term nazi.
It's just a joke. Why is everyone being such a b*tch?
I'm just trying to help you understand why this would be very offensive to other people. Nothing good would come from using terms like these.