If you ask a liberal what “tankie” means you will get a response that sounds a lot like if you ask a conservative what “woke” means. The two main developers are communists, trying to collectivize social media. It is very shocking. 🙄 They develop the software transparently, out in the open, along with many other contributors. They also operate lemmy.ml, the very first Lemmy instance. Dessalines has a collection of essays he’s written on Github. If you are concerned about his beliefs, I would go straight to the source rather then taking third hand rumors on face value. As for the rest of the network, each instance (such as lemmy.world) is operated independently. The whole point of federation is to decentralize control over the network.
It’s been a while since I used Arch, but it was smooth sailing while I did. In general, gaming means Steam, and Steam ships with its own runtime so it is not really impacted by whatever library versions are packaged by the distro. Gaming is a very common use case. You’d have to pick a pretty obscure one to find something where it isn’t tested and somewhat streamlined.