I do think @Precipice has got it. It’s two separate issues. You’re talking about a religious meaning and then a “foreign” language (ie one you don’t speak and is not the official language of the land in which you reside).
So it’s not the equivalent of saying “not kosher.” The Jewish equivalent would be maybe more like peppering your speech with Yiddish phrases. Like saying, “Oy vey!” when something goes wrong or is frustrating. If you don’t think it would sound strange to insert random Yiddish words into your speech, then perhaps it is not strange, in your opinion to insert random Arabic-Muslim words.
So I do think it’s more about foreign language. If you are in an Arabic-speaking location, I think it would probably be fine to use it.
But you’re also running into another problem with single loan words from other languages. While I’m not Muslim, I witnessed this exchange between my friend’s little brother and her mum when all three of us were teenagers:
Mum: ”When are you going to bring me your clothes to wash???”
Brother: He was flipping through a magazine in the lounge and just went, “Eh, inshallah, inshallah.”
So I feel like you might be romanticizing it juuuuust a wee bit? But you’d do better to talk to an actual Muslim about this (as obviously, I’m as far from an expert in someone else’s culture as a cat is from the moon).
Maybe your idea of bringing back Godspeed is better. I mean, why not? My gran used it and she only died in 2020, so it’s only been out of circulation (if it even IS out of circulation, if my gran was the last person on earth using it, ha) for three years. You could be responsible for its comeback, OP!