I also have a dd reading my NAS once a month. It catches bad sectors and forces issues into the open.

I just use dd. It can take days, but it’s worth it.

I’ve used these kinds of disks in my NAS at least since 2017 with no issues. Just test thoroughly before using. I usually do SMART short and long tests, and then a bit by bit write and read of the entire disk. I’ve caught a couple that failed right away. If it passes that, then it’s usually good for years.

I’ve been using KeePassDroid. Nextcloud has an option to set files to favorites which keeps them local on Android.

I used to use Dropbox, but switched to Nextcloud years ago.

BitTorrent

TT-RSS has worked well for me since Google Reader was killed.