to moderate a community bots are helpfull and this would be great.
There also should be a posting limit per hour / day so we don't flood everything.
Automatic "sync" a subreddit to lemmy is okay, but depends on the content. There are enough user who don't want to see their content on other platforms. And we don't want to anger these user.
Also mark / link the original poster would be great to appriciate him. Or ask if we can post the content here too or ask if they wanna join and post their stuff directly here
User will also follow the community with most posts. If there are 10 same communities on different lemmy instances I would also follow only the two most actives.