Sadly the system cannot be used easily for any applications storing personal information since your identity is tied to a blockchain and the GDPR requires companies to make information deletable.
The reliance on abstract art for trying to make their points come across are still to vague for me to give the project a try, but who knows, maybe in another year or two the project and its concepts will actually be understandable enough for me to give it a shot.
As to your second point, I'm curious if any decentralized system will ever allow for full deletion of information once it has been replicated by another client. Any gossip protocol, or decentralized CRDT document system has to take into account that a client will go offline and retain information once it has been released into the wild. Whether or not a request to "delete" or hide that information is followed through with is almost impossible to regulate. It's perhaps more important to realize that what we publish, may always exist out there.
That being said, clients could randomly ask for "tombstoned" information to verify that other clients comply to a delete request, but it will likely always exist somewhere.