Your descriptions here of the "worse things" leave a terrible lot of clarifying information out. Information that could be helpful.
"Like God ordering killing of every living being, Men, Women, Children, cattle, family dog." When God explained to Abraham that his descendants would be captive for 400 years and then they would be allowed to go into the Promised Land, he explained that time frame was such because the "sin of the Amorite was not yet full". God waited for centures, giving the Hebrews a time to assemble as a nation and giving the ungodly peoples of the Promised Land a time for their hearts to soften. God is immensely patient. He's not the cold killing machine that many make him out to be. There were lots of people in the Promised Land who assimilated into the Hebrew nation - the first, a whore named Rahab. She had the privilege of becoming King David's great-grandmother. I've read the Old Testament line by line and verse by verse discussing it together will people who enjoy the same. Some like knitting or putting old cars together. I like reading the Old Testament with like-minded people. We are always astounded at God's mercy upon people. And we are not offended by his wrath after that mercy has given people a tremendous opportunity to become righteous.
"God killing a guy for not getting his brother in law's wife pregnant" Are you talking about Er and Onan? They were brothers - Judah's sons. Er was super evil and died. Onan should have married Er's wife, Tamar, and given her children. Legally, any sons born to her would belong to the dead husband, Er, and would inherit his double portion. Onan did married her and did disgrace her by not inseminating her during their intimate times. I won't explain all that - you understand. He was greedy and wanted his portion, plus his brother's double portion. He was disobedient to his father, to God, and disgraced his wife. God killed him. He was not some innocent man who did nothing wrong.
"Guys burning their daughter in sacrifice to God for winning wars." As far as I know, there was only one man who did this and it was Jephthah. He, by his own admission, he was devastated at the outcome of his vow. It was a stupid and foolish vow. And God had nothing to do with his making of the vow. It was a time, the Bible says, that everyone did what was right in their own eyes And that usually was the wrong thing bringing terrible results.
"God sicking bears on children to tear them to pieces." These weren't innocent little kindergarten children that ELISHA called two she-bears own upon. The Hebrew word, "na'ar" mostly means young men or youths. It's used once for a baby and a few times for children [still vague], once for Isaac when he was 39, Joseph at 20.....you get the point.
Elisha had just watched Elijah taken up in the whirlwind. He is now headed for Bethel - a place not known for being welcoming to true prophets of God. These "youths" would have to be old enough to understand the rejection of a true prophet for them to have rejected Elisha. They mocked him, told him to "go up" [or fly up like Elijah] - intimating they did not believe that story and in their mockery of God's prophet - they mocked God. Elisha cursed them and two she-bears came and cut up 42 of them - implying there were more than 42. It doesn't say the bears killed them. I can well imagine that Elisha facing 42+ young men mocking him and mocking God had no other recourse in his mind.
To me, in-depth reading and praying over sensational texts gives the light of truth to God and people.