AutoDapp: a proposal to decentralize existing web apps

And the benefit of doing this is to allow other users to be able to validate the integrity of data and ensure historical changes cannot be overwritten?

So who pays for the transaction storage costs? and how does this validator thing work?

I don't think this is a useful definition. Blockchains are about trust and control, not Byzantine fault tolerance.

The tl:dr; appears to be "we built a blockchain based query logger" where essentially the consensus appears to just be that it is valid SQL, and defines an ordering of the statements. Then once everyone agrees to apply the change, then it is applied... With (AFAICT) no interaction with the DB during the consensus process?

This seems to be a bit naive of features like locks and transactions that are critical to most DBs, so while maybe you can define a global ordering of statements, the execution of those statements may be nonsensical and result in a lot of failed transactions. For example, it seems like you could grind the usability of the system to a halt by flooding the validators with 'valid' SQL designed to create as many conflicts as possible that would cause a ton of writes to fail to commit.

I agree with the desire for more services to become decentralized, and this is a novel idea, but (IMHO) more and more the technical hurdles of blockchains often bring more challenges than they solve.