I use inbox.eu

https://foldingathome.org/

I think nostr is the better decentralised social media technology, but I fear you might feel left out by the people that frequent it (as they would here).

The first, single folder for all of them.

I have a shared syncthing folder on all my devices

Syncthing is not limited to local network. It’s hole punching is one of the major features

Youtube channels. A simple timeline of uploads, only showing chanels I care about.

Forgot minecraft server

Have it pretend to be Gandalf working in a coffee shop

https://github.com/gristlabs/grist-core ?

https://github.com/awesome-selfhosted/awesome-selfhosted?tab=readme-ov-file#resource-planning

An easy out of the box solution would be a synology NAS.

For HW I personally use a NUC. If I were to build something today within said budget, I’d go for a second hand thin client.

For example the Thinkcentre M720q Tiny I can buy for 225EUR, coming with 8th gen core i5, 8GiB RAM, 256GiB SSD (1). Idle consumption is around 5W.

I use syncthing to sync folders between phone, tablet, desktop and my home server (a NUC).

Then rsync on a schedule from the server to a second off-site server (also a NUC) as backup, connected through zerotier.

I know of truenas, which is a more NAS like solution, but haven’t personally used that.

I use Feedbro, a firefox addon