The problem I have with channels is that of administration and problems festering in private channels. However, I could see how this could be beneficial. I'd put a maybe on this one. Beerchat looks like a good chat mod. I do like keeping things simple, but I imagine that if the game or server were very busy channels would be necessary. We've never been that busy. The server and internet connection are not great enough to support over 32-64 people at this point. We typically max out at around 12 - 15 people from what I've seen. Could do better if the server perfroamnce and serverlist ranking were increased. I'd like to eventualyl do that. Probably once I move I can get the best Internet possible.
For babelfish, I've seen this before in a server but have never used it. I likely wouldn't add it as I like the language barrier being part of the communications. We can work together to communicate and overcome this. Also, it uses internet services to get translations which requires disabling a security settings in Minetest. I haven't been required to do this for any mods so far and would not be inclined to include babelfish because of this. Very nice concept though. Nice name too :)