On the 1-1 part, ‘all’ is an aggregate of anything subscribed by someone on your instance, but hiding them from your feed en’masse should be doable from either a client or web frontend. Maybe check a few different ones and see if any have that feature.
1-2 is more difficult since there isn’t a central list of all communities on all instances, but there are some sites that you can browse through several like lemmyverse.net/communities?nsfw=null for a starting point.
As to 2.0, it’s a preference thing. Some people like RSS feeds to have stuff come in, some want a more personal touch. If it’s actual news of good province I’ll keep them, but garbage memes can go.