Thanks this is very useful feedback. Especially the search box in community sidebar would be very useful and easy to add. Formatting for community ids should also be easy to improve. A bit later when I have time I will implement these things, and then make a post in the Help Design Lemmy Series regarding search.
By the way basic reading is working for me in Tor browser with JS disabled. Though buttons like switching Local/All, sorting and of course forms like register, login and search are not supported. We could use contributors to help fix these things.
This is already implemented, admins can specify a “suggested” multi-community which will be shown next to Subscribed/Local/All just like you say.