So, what do you think His position is on for example slavery and the stoning of disobedient children? The God of the bible clearly endorsed these practices in the past. Does he still endorse them?
Yes. I accept God for who the Bible says He is, and love Him for it. He is not only infinitely merciful, but infinitley just. I agree with the U.S. Supreme court that capital punishment for certain juveniles is necessary (though He also reveals in Ezekiel 33 that He does not delight in the death of the wicked, but rather that they turn from thier ways and repent.. In the part of the law you name, it is not clear to me that the "children" to be stoned to death are not in their 20s anyway.
Is that any less just than our current system that takes childern from parents just for spanking them in public? That does not allow the parents to discipline an unruly child so they grow up wild and police have to shoot them later?
The "slaves" were not the sort of slaves that Americans once kidnapped from Africa. A better translation would be "bond servatns". After 7 years they were supposed to be let go, unless they decided they wanted to stay with their master for life. There are a lot of people out there today who are too plain stupid to successfully navigate the modern world on their own. They would be better off if they attached themselves to some well to do person and became their household bond servant.
The reason this God does not seem cruel or harsh is 1) I am not brainwashed by liberal propaganda and 2) Jesus took the penalty for sin that I deserved. God is not strict on us but lax on Himself.