No. God did kill all the firstborns of Egypt. He sent the angel of death to destroy them as punishment for not letting Israel out of captivity. And he also directly ordered the destruction of Jericho and Ai. You don't sound like you are familiar with the stories.
I think you got me a bit wrong here. I'm not saying that
according to the Old Testament, God didn't kill the male firstborns of Egypt. I'm saying that I do not believe the factual accuracy of the Old Testament, but I do believe the accuracy of the New One.

As I said earlier in another thread, I believe Judaism was obviously a step forward, but I also believe stories such as the Angel of Death coming to kill all male firstborns of Egypt are intended to scare people. That's the main difference between the Old and New Testament.
Edit: BTW, I did read all the Bible, and I am very familiar with the story (exactly analyzing the Old and New Testament got me to these conclusions). You got me wrong, because I didn't say the Old Testament doesn't say so, I meant what I explained above. ^^ That's all.
Currently, it's not, and that's great for Christianity. Christians used to do a lot of violent stuff too.
Not all of Christianity though. Again,
you're confusing the church with Christianity as a whole. For example, God isn't responsible for what the Conquistadors did in South America... The difference is that the Christian God condemns such practices, while Islam does not (they were pagans, aka nonbelievers). And I'm wrong when I say "the church", as there is more than one church - I have yet to see the (Edit: Corrected, partial name and messed up link)
Chalcedonian Protestant Syriac Church burn someone on the stake, or a Coptic Orthodox declare that whoever does not follow their religion deserves dying.