Perhaps something like your plug-in system could be a good start for compute, but it also doesn’t seem like something that should be a decade away after launch.
Essentially you want some elders to have consensus of the result of some compution running on a VM. Ethereum has made a deterministic subset of web assembly for Ethereum 2.0, I guess that would be a good starting point.
With the consensus mechanism in place and already existing VM that can be used, that’s the core parts already, no?