Boone Gorges

CUNY Academic Commons

Allows admins to import data from an arbitrary RSS feed into their BuddyPress sitewide activity stream
The plugin imports RSS feeds every hour. You may find that you need to decrease your Simplepie cache time to make it work: 
 add_filter( ‘wp_feed_cache_transient_lifetime’, create_function(‘$a’, ‘return 600;’) ); 
reduces the RSS cache to ten minutes, for example. Put that in your bp-custom.php file if you are having problems with the plugin.
At the moment, the plugin uses the Author field from the RSS feed to look for a matching author in your WP database. If it doesn’t find one, it uses the unlinked text ‘A user’, as in ‘A user edited the wiki page…’.

BP External Activity

Allows admins to import data from an arbitrary RSS feed into their BuddyPress sitewide activity stream

jmarreros

This Plugin allows to use an external image as Featured Image, this can be especially useful if you house your images in another location.
This Plugin is compatible with Nelio External Featured Image Metadata, so you can reuse your data in case you want to uninstall Nelio Plugin.

External URL Featured Image

It is what I was looking for: simplicity.

$external_image = get_post_meta( $post->ID, '_dcms_eufi_img', true );

Works well for me

Use an external url image as Featured Image for your posts, pages, and other kind of post types.

BP External Activity vs External URL Featured Image