Thanks for keeping a very civil conversation! Love you, man.
I suppose that would be a more accurate description. People most certainly have done some rather horrible and evil things in the name of Christianity. That doesn't point to a flawed God, just flawed people. I'm by no means perfect. I fail every single day.
A gun can be used to murder people and destroy lives... or it can be used for protection. It's all in how you use it.
All of these questions are based out of the Old Testament of the Bible. This is what's commonly referred to as "The Law." As a follower of Christ, I am not under "The Law." I am under God's grace. "The Law" was put in place by God to show people that it was impossible to keep. "The Law" was put in place to show everyone that we need a savior.
In the end the Bible is not a law book or a book of regulations, the whole point of it is to get into a relationship with God. God loves us all and desires a relationship with us. That's why God sent Jesus on that cross to die for our sins. Because of His love for us. Because He wants to get close to us. But love comes packaged with free will. You can't have love without free will. So we have to choose Him. So I may not be able to answer all of your questions, but I do know that God loves you.
Edit: Without having my bible handy, I can at least answer one of those for you. With regards to the shellfish thing, there is no longer a ban on what we can eat as per the book of Acts (Chapter 10) when God gave Peter the dream. Technically, even sooner than that when Jesus said, "It's not what goes into your mouth that defiles you; you are defiled by the words that come out of your mouth." Matthew 15:11.