Limit checklist by the current user

Use the same technique as $checked:

$disabled = ( $ed->ID != get_current_user_id() ) ? ' disabled="disabled"' : '';

your code:

foreach ($alleds as $ed) {
    $checked = (in_array($ed->ID,(array)$currenteds)) ? ' checked="checked"' : '';
    $disabled = ( $ed->ID != get_current_user_id() ) ? ' disabled="disabled"' : '';
    echo '<input type="checkbox" name="currenteds[]" value="' . $ed->ID . '"' . $checked . $disabled . '"/><label for="ratings[]">'.$ed->user_nicename.'</label>';
}