Removal of output should work by creating a plugin with the following code in start.php:

<?php

elgg_register_event_handler('init', 'system', 'no_friendly_time_init');

function no_friendly_time_init() {
    elgg_register_plugin_hook_handler('format', 'friendly:time', 'no_friendly_time_hook');
}

function no_friendly_time_hook($hook, $type, $return, $params) {
    return '';
}

These entries are created by the Profile Manager plugin. There's a plugin setting on the Profile Manager's settings page to disable creation of these river entries.

Thank you don't know how i missed that.

How do i add the poster uid and the the uid of the person tagged in a post to show on the rss?

it looks like this:

http://socialcrypto.net/activity?view=rss