No.
Developers of opensource software have been coordinating around complex problems for decades. I don’t think lemmy or mastodon can contribute much to that.
I don’t see why the fediverse needs to be co-opted into any particular political ideology. All political interests are free to create their own instances and / or use the fediverse as they wish. I don’t think it’s any more suited to left-libertarian than any other ideology.
I also don’t see the fediverse being a “new landscape”. The majority of people will always gravitate towards well funded corporate platforms. I would be really happy with the fediverse staying as it is now, I mean of course everyone is free to join but if it became the new normal then I’d have to find somewhere else to spend my time.
Nothing. I never bookmark or save anything other than research in which case I take notes with urls.
I just search for what I want to read.
I don’t ever recall trying to find something that had disappeared. If that happened it would be a small price to pay for not having to archive the entire web.