God is still a murderer and a sadist.
Your description of God seems to be anthropomorphic, in that you are assuming it is wrong for God to kill a person, as it is wrong for a person to kill a person.
This thinking is faulty, however. Remember that God is not a human, and that every human owes everything, including life, to God. God is the creator of all life, so He has every right to take it away whenever He decides it should be taken.
God is no more a murderer for killing people than I am for deleting letters while I type this post.
Furthermore, remember that
all death comes from God, so if God killing people was murder, then God would have to make people immortal to be a "good" God, and if that were the case, then no one would ever get to Heaven.
But why is it that in some parts of the Bible, it was mentioned that we are either fated to end up in Hell or Heaven? We have no actual say in the matter.
Could you give book, chapter, and verse for that? I don't remember the Bible saying this from any of my readings...
I'm not a skeptic about God's existence, I'm a critic of His actions.
Here's one little logical problem. If you admit God's existence, it follows that God is a lot smarter than you are now or could possibly ever be. It also follows that God has more information than you do now in your judgement.
Suppose a toddler criticizes the President about foreign policy. Now multiply that difference by about infinity, and that's you or me criticizing God.
I understand God's decisions must often seem wrong to you, but as a human, you can only know the most infinitesimal fraction of what God knows, and understand even less of what you know. God has not such human limitations.
You must admit that one big emphasis point of the Bible is faith. When God does something a human doesn't like or understand, the easy way out for the human is to say, "God is just bad."
True faith, however, means recognition of one's own faults and shortcomings. Being faithful is hard, especially if it entails sincerely admitting that God knows best, that he's not just evil.