Thanks for the link. I'll have a look at that. Currently I use PieFed. Which as some way to go, but some gread ideas.
Concerning the All-feed: Using that to find new communities would be something I also do. But I heard people just use that instead of subscribing. And one or two people said they then just block all the communities they're not interested in. I guess that works, too. I haven't tried myself.