@Patrick and many others will find this interesting:
More than 25,000 people were interviewed for the survey - for BBC News Arabic by the Arab Barometer research network - across 10 countries and the Palestinian territories between late 2018 and spring 2019.
@Faizal_Ali do you come from an Islamic background?
Atheists do you recognize any distinctions or differences between atheists from Christian versus Muslim backgrounds?
There are differences and distinctions between all atheists. We are a very motley bunch. However, I am intrigued to see what differences there are between modern atheist groups that emerge out of different religious backgrounds and cultures. How much of the religious culture is carried over? How much are we affected by the society we grew up in? It is an interesting question.
Depends on in which sense you mean. Doctrine, yes obviously there are differences there.
Degree of religiosity? In my experience Muslims even here in Scandinavia are generally much more religious than Christians. In Denmark, most “Christians” you meet are sort of cultural Christians who go through the motions on different occasions. I’m not sure if really they believe any of it. They show up in church for marriage and funerals, and dance around a pine tree on Christmas while eating themselves half to death (but hey, so do I). That’s basically it. If they’re religious they keep it private. In fact you rarely meet someone who ever speaks about their religious beliefs unless you very explicitly ask them about it, which could probably be considered somewhat impolite depending on the person. I don’t remember ever having spoken to very explicitly religious Christians besides Jehovas Witnesses who come knocking on Sundays once in a while.
Muslims are generally much more literal or invested in their beliefs, both in how they dress, what they eat, how seriously they take and celebrate religious holidays, and so on.
Of course these are broad generalizations and only reflect my personal experience, so exceptions are bound to exist.
In terms of arguments for belief I hear muslims make(which I mostly encounter on the internet), they’re basically the same.
Oh I see I misread the question, you were asking about difference between atheists coming from different religious backgrounds, not differences between religious people.
I don’t know that I personally know an atheist who used to be a muslim so I can’t speak to that.
I don’t personally know any atheists from muslim backgrounds. But I can recommend a couple of books on the journey from islam to atheism:
Ayaan Hirsi Ali, Infidel: My Life (although in her later book, Heretic, she appears to have somewhat-returned to religion, advocating for a reformed islam)
Maajid Nawaz, Radical
Ali A. Rizvi, The Atheist Muslim: A Journey from Religion to Reason
Yes, I do.
They’re all like me, whatever that is. 
Well there you go. You don’t know till you ask 
How are atheists treated in Muslim majority countries? Does it differ depending on the country? I have heard Turkey is more secular than others, but would like to hear from someone who may know something about it.
I’ve lived all my life in Canada, so no idea.
Not yet you haven’t. 