My idea is different. Instead of playbook yaml, playbook go source, that compiles to a fat binary that is transferred over ssh. That decreases the dependencies to ssh only on the target hosts (no python). The framework would include an idempotent API that matches all the tasks that Ansible provides.

Yes, you are thinking about the same. I would just use YAML for the things that can be configured.

Is execution speed really an issue? Unless you're parsing millions of lines of YAML, it's difficult to believe that's a bottleneck.

I reckon a good benefit would be static typing and intellisense.

It is, Ansible is pretty slow at scale (100+ servers).