Definitely second explicitly stating the “fully qualified” !community@instance for instances not in your home instance. Similarly, include the instance name when viewing the sidebar or other user’s profile for remote instances.
I would also very much like to see a share option added in posts and comments, with possible options to Copy Link and to Open in Safari. This could be available via an explicit share button, in an ellipsis/more menu, or via long press on a post or comment.