Sure!
We are using Blockstack for authentication; it is a platform to have your identity safe with the help of blockchain.
Scalable? It is easier as all the works are done in the client-side, so no server pressure there, and your data will be stored on the storage provider of choice although we have a default one with 10GB free storage for all the news users. (Always encrypted!)
In the future, we will provide extended options like self hosting for enterprises.
Yes. But it gives us the power of making sure everything is encrypted and accessible from anyway, and no one beside you can access your data! As for storage, it is configurable, and you can move it anywhere. But you have 10GB free plan if you join us now.
Not at all. Your identity is encrypted with the master key just like when you make a BTC wallet. You can save it and use it even if our servers go down; you can have or use another node.
Also, you can choose or make another storage provider to host your docs. We are cool; we want to give people a more secure option ;)