most of this quotes are taken out of context. Brother Osama gave you excellent links.
All this has already been explained and their claims refuted. For example, read this:http://comparativreligion.blogspot.com.eg/2012/11/quran-2191-and-slay-them-wherever-ye.html for the first quoted ayah. Just type the verse number here:http://bemuslims.weebly.com/muslims-search-engine.html and you will find excellent responses Inshaa' Allah.