We all go our own ways. Over the later years I’ve added features and with it the inevitable complexity. Self-hosting my own data has made my care more about what goes on in my network. I am not quite at the stage of adding VLAN’s but it will probably come.

A router provided by an ISP is not your hardware, thus any network behind it is by definition not controlled by you. There have been numerous cases where they have backdoors or known admin passwords. In cases where there is a wire type transition (for example incoming over coax or fiber) it might be necessary to use it though. Same if it is necessary due to your contract.

In my cases I always turn off the wireless antennas and switch it to bridge mode, then place my own router/firewall device behind it.

Edit: still learning to spell.

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.

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.