Supernault is actively considering having the flagship loops.video server function as the centralised service for the For You algorithm.
That sounds... potentially counter to the goals of the Fediverse. If it's its own open-source and hostable project with an easy switch for admins to provide a different algorithm then I can see how it would be a big leg up for better discovery, but if it just locks you into phoning home to loops.video then that is terrible.
I have thought for a while though that search / indexing should be a separate Fediverse service to allow even tiny instances to make use of large-scale search, but only as long as it remains open for anyone to host an indexer.
IMO, yes. HDDs are always going to be a bit noisy, but the consumer grades keep it fairly classy. The couple of HGST drives I got from ServerPartDeals are noisy in the "grating" way. The volume is similar but the noise is not in the normal pleasant range. I am only fine with it because my server is in another room.