Only downside with hetzner storage share (compared to other managed hosting providers) is, that you need to run your own collabora instance on a VPS to use nextcloud office
And ffmpeg isn't available on most managed hostings
Privileged ports can be used by processes that are running without root permissions.
So if the sshd process would crash or stop for some other reason, any malicious user process could pretend to be the real ssh server without privilege escalation.
To be fair this isn't really a concern for single user systems.
But setting up fail2ban or only making ssh accessible from a local network or VPN would probably be a more helpful hardenening step
And regarding port 2222 it is the most popular non-provileged port used for SSH according to shodan.io So you ain't gaining much obscurity
You can lock the files you're sharing, so that other people can see them, but are unable to download. Unless they are specifically allowed to do so. Many people that do this only unlock the files if you have something good to trade (that's also locked) or you pay them
I don't really get, why people praise soulseek so much. It lacks the resilience of torrents. There is much cool stuff, but no quality control and structure. And the cool old stuff is artificially locked in order to keep it rare.
Git is bad at tracking binary files. So it's not a good solution for backups. You could use something like restic, Borg or Kopia from termux
Here's a good guide on how to do it with Borg that could easily be adopted to the other tools https://neverpanic.de/blog/2022/01/25/backing-up-your-android-phone-with-borgbackup/