b) you DON'T NEED to join all channels if you are not interested. You can join all and remove them later or you can select them before join the folder
c) you can remove all folder and channels, or you can remove just the folder (= so you can join other folders ...) or you can remove a folder by keeping some channels
We noticed that Telegram has some problems with the sharable folders, now you can find all channels on https://t.center/addlist/lWUc3G65IcM5MGQ5 again, since they don't auto update the channels automatically, even if we added new on the folder ...
To create a chat folder, go to Settings > Chat Folders on any Telegram app. Pick the chats you’d like included, and give it a name – your folder will appear as a separate tab in your chat list, like Work or News.
Chat folders can have up to 200 chats each – and any chat can be added to multiple folders.
