[I need to point out that my answer needs to be viewed in the context that I don't believe we have an eternal soul, I believe god can destroy the soul as Jesus said, and therefore I don't believe there will be eternal suffering for us etc etc]
Your quoted genocide event isn't nowhere near as bad as killing the whole world by drowning. That would have been a better charge I think.
Nevertheless, God himself will take your life eventually, it makes little difference if he gets someone else to do it, or how they do it.
But before we even get to any of these later scriptures we need to ask why he allowed Cain to kill Abel, let alone anything that happened later on. We need to ask why he allowed Satan to be a catalyst to accelerate a cascade of sin. We need to ask what kind of god would deny us eternal life and why.
Then we will do much better to understand why he also said he hates violence, why he said that he wishes that no one had to die, and how he longs for everyone to be saved, and how to him all are alive, not dead.
The bigger picture of course is not easy to see if we dwell only on the mortifying horrors of what he has allowed and even pushed for. (Funny, nobody complains if violence saves their own life.) The sooner this tragic drama of 'man in charge' comes to an end, the sooner he can get things back to the way he wanted them to be in the first place, without violence or suffering of any kind.
Giving us free agency was a massive risk. Once our negative side was revealed it's too late to put the genie back in the bottle. Better to do what it takes to get the lessons over with. Once eternity is given it can't be taken back (or it wouldn't be eternity). The stakes are therefore enormous. No one can be allowed to 'do a lucifer' and be given eternity with the idea that sin is ok and doesn't matter. No one can be allowed to be locked in forever with misery in them. There is no other way except to live through and understand the consequences of our negative side. I don't know how many people he intends to make, but the sooner this violent show wraps up the better.
Is the suffering now worth enduring to gain an eternity later on? No contest.
God of-course is the only being who can commit genocide and still be able to reverse it later on (which he promised he will do). And that applies to him letting
everyone die, not just some pre-emptive action between two already barbarous groups in some ancient land designed to elevate a certain group for a certain purpose. He also let himself become a physical personal victim of our violent solutions, so nobody can lecture him on just how wrong violence is.
Should we be pi**ed off with God for letting people suffer? I say yes, it's ok to be, or we'd have an odd sense of justice if we weren't. Does God allow people to get hurt, even command that they be hurt? Yes, no argument from me. Does God give a **** about it? Does he know what he is doing? Actually, yes. And that's what many people don't seem to get.
We have to take all of God's words into account, not just those that bother us.
Genocidal, yes, by our standards. Maniac, no.