@wakame @gilest File transfer could be done with something like magic-wormhole, there really just needs to be a user-friendly UI (problem is that it's a synchronous-use program).
Something like NNCP + syncthing for uninteractive multiple-retry would also be an option (based
#AsynchronousCommunication).
(Supporting Veilid would be useful for all of those, since it takes care of the TURN-style & relay shenanigans necessary for NAT traversal and other similar annoyances.)
The homepage/blog can just be content-addressed, but it'd need to be in the Freenet/dat way rather than IPFS: not just addressing the content but incorporating an encryption key so that various caches along the path that do not have the capability/link for the decrypted file can't decrypt it. (Yes, all of those support mutable/updatable documents.)
(I'm working off the notion private = restricted access, otherwise encrypting the document is completely unnecessary.)
Calendar/Email can also be handled with NNCP over Veilid. Calendar more specifically could also be handled with a mutation capability for an encrypted content-addressed document (which I suppose makes it more a reference to another document then but whatever, precedents already exist as I mentioned prior).