This is definitely an aspect of social media in general. An argument can be made to register your profile and let it lie dormant just to avoid it being hijacked. Hijacking has been an issue in BlueSky during the Twitter migration bursts. Sure - the companies can use the registration for statistics, and the decision to register is somewhere between performance and personal integrity.

Yes, although MySQL/MariaDB or PostgreSQL are the more robust options.

For personal use. As someone who has all my non-trivial creations, including dot-files and scripts I replicate between machines, in repos since CVS has a thing it’s a habit. Version control. This stuff is mostly private but not secret, why should I have it public?

Edit after spell check.

Without knowing what ypu plan is in detail, here’s one example of a plan for a NAS…

• Flash your SAS card or get an LSI card you can flash to IT mode.
• Install TrueNAS Scale and set up your ZFS volume with your existing SAS drives
• If any drive fails, exchange it for a SATA with at least the same size and re-silver.

You wouldn’t need to exchange all of them at the same time as long as the one you are swapping in can hold all the blocks the old one did.

Switzerland is contradictory in many ways. At the same time as they go for on-prem or sovereign cloud (laudable), they are passing laws that chase away privacy first companies such as Proton (less than optimal).

Yeah, your data is taken hostage. When cancelling the subscription it’s a good idea to delete everything manually before the account expires. Even if you can’t guarantee Dropbox haven’t just flagged the files as deleted, it signals intention. I did this when migrating to pCloud and haven’t received any reminders from Dropbox.