Most who use Arch prefer to use a customized tiling window manager instead of a desktop environment. I tried using i3, and I do understand tiling WMs, but they’re not really for me and I won’t be able to do a crazy design out of them.

The colors are not that great. It’s like a beautiful city being covered in grey smoke.

There is a variety of instances for Firefish, such as kitty.social. One weird thing I notices is that the Firefish logo is not consistent across all instances. ThatOneCalculator, creator of Firefish, was recently involved in some drama, so some instance owners put an alternative logo instead.

I like Firefish, I am on a Firefish instance myself, and I feel really good about it. It’s fun to use and it federates with Mastodon most of the time, and with Misskey some of the time. Unfortunately, microblogging on the fediverse is not as straightforward as forums on the fediverse, as they’re a lot more fragmented and there are 5 or 6 different platforms instead of 2 like we have here.

This page has some good recommendations. I suggest you to do research about each solution before picking one that fits your needs.