[ahdinosaur]

> Can I choose to sync just...

at the moment no, but it's likely we'll move content off-chain (%QJEpN8LN1t3BrIkUQ3WoOMWRsMArbVUZCpTeBYcuqfw=.sha256) so you would only need to sync the signature chain metadata, then could choose what content you want to download or delete.

> But now I think Manyverse might just be a "pub" on SSB

Manyverse is a mobile app on SSB, much like Patchwork is a desktop app. it uses all the same peer-to-peer network, including the existing pubs (as in there are no pubs specific to Manyverse).

> shall I have do everything all over again if I ever to go for a desktop app or any other app on any device

if you want to use both Manyverse and Patchwork, yes they will be separate keys each with their own feed, to be merged as the same conceptual identity, see this comment: https://news.ycombinator.com/item?id=18067100.