So...hang on... you are saying that this a medicinal painful execution...applied to a 'sickness of error' as a means to avoid an eternity in a realm (which doesn't actually exist in Jewish mythology) but was created by the same diety?
The Jews of Levitican times believed all people (good or bad with a few exemptions like Enoch) ended up in Sheol. Which wasn't a place of punishment until it was translated into Greek and became associated with Hades or translated into medieval Nordic/Germanic languages and became associated with Hel.
The stoning for them was a form of living burial (the dead were buried under a pile of stones) not a cure or a mercy, just a disposal.
Catholics of a few centuries back thought burning people accused of witchcraft after confessing (usually after torture) spared them from Hellfire. Your view is more akin to that evil nonsense than the evil earlier nonsense.
Either way the God you are describing is one hell of a mixed up character.
He makes man with free will, orders him not to do something, then punishes the species with painful death followed by eternal torment if you don't say sorry and agree it was a fair punishment.
To paraphrase Flash Gordon, this God is a psycho or maybe it's just his followers?
The Old Testament promotes child slavery. Presumably you don't think this is a godly thing anymore but when we look back at bad things like slavery we don't say it was good then but now it's bad.
We say it was bad then but most people didn't know better.
You seem to be saying stoning people to death was good then but now loving people and hoping they will stop being gay with each other is a better way.