Going to extreme measures to eliminate all abuse is like attempting to put a lid on the bucket to prevent a few crabs from escaping and comes at the expense of making it harder to add new crabs to the bucket.

I think this is right. I think extreme measures are not necessary. I think how I use downvotes today works pretty well but will never be perfect so I am always adjusting. I am not god; I am just a person. If I downvote someone there is always a path forward with me. But that is just me, other users who downvote would also need to be reconciled with in a positive way.

I have seen a lot of instances where people get off blacklists. So when people freak out and do crazy stuff in reaction to a downvote they just make it worse.

Whatever the code allows are rules other stuff is just customs and culture

This is correct!

Most of the over reactions related to downvotes is culture and norms which is reinforced by other users. People will freak out after being downvoted and then other users encourage them by saying their freakout is justified. If someone just said, "hey, downvotes are not that bad and you can probably get out of it if you relax and are humble," that would go a long way. The other problem is most people let their ego control their life and the ego will consume you if you feed it.