Interesting how your arguments take a different twist than others. The answers are actually sourced much deeper in Philosophy than anything else.
1. The math may be right. Are the Jews back in the land? Is Israel not the center of worldwide turmoil? There are only a few religions that have been preserved over time that dominate the world each of which are rooted in the beginning. The math may be better than you think.
2. God as mass murderer? I condone killing in certain instances. Surely your from TX, you do also. If you accept there is a God then his "murders" cannot be judged because by God's nature we do not have all the information as would He. If you deny God upfront, then how can you attribute the murder's to Him? Maybe it is Humans using Him as an Excuse?
3. As for stoning etc. God hates when we deviate from his plan because that deviation causes much more harm far beyond the act itself. This harm has aggregated into a world full of death, suffering, destruction, etc. God sees how each individual departure combines to the whole. That too would devastate me, as it would I am certain, you. If you knew, like the Butterfly effect, that a single action or set of actions on behalf of your child would cause their immense suffering over life and immense suffering on others, even if it seemed harmless at the time, how aggressively would you want to stop it?