I expected you to write that. That is why I wrote this rebuttal before you wrote your post:
The issue is that since the output state of a contract in one partition could impact the input state of a contract in another partition (and there is no way to prevent this unless no one can write any user data into the block chain), then validators in each partition need to trust validators in all partitions, thus they really need to verify the scripts from all the partitions else the consensus-by-betting doesn't reflect rational incentives which the math depends on for rational (versus randomized noise) convergence, i.e. the game theory of the consensus model is impacted. But if all partitions have to validate all partitions, that destroys the scaling gains from partitions.
The point is there can't be partitions with programmable scripting. Coasian boundaries are subject to destruction by entropy.
I was talking about PoW chains - casper is a horrible idea IMO.