Good feature requests, but it is out of scope with the plugin.
1) BuddyPress doesn’t offer this feature for the friends component, so BP Follow won’t add this functionality into the plugin as well. However, this could be accomplished with custom code.
2) What theme are you using? If you’re using bp-default it should work properly. BP’s universal theme compatibility layer doesn’t use an AJAX loading image. For example, try using the “Add Friend” button on a theme that is not bp-default. You won’t see an AJAX loading image. For more info, see: https://buddypress.trac.wordpress.org/ticket/4951
1) Ok. I will go with some custom code.
2) I am not using the BP defealt theme. You’re right, all BP buttons are without an AJAX loading image. I understand from the discussion that this is on the BP roadmap? In the meantime, is there another solution to indicate loading time for the user?