How to Override OG Group Owner Permissions for view/edit group content?
Because group owners are considered the equivalent of "Super administrator" (user 1) of their group AND group content, which I happen to totally disagree with, this wound up being solved using hook_node_access() as follows for Question 1:

/**
 * Implements hook_node_access().
 *
 * Runs every time a user tries to edit an endorsement
 */
function icme_admin_node_access($node, $op, $account) {
  if ($node-&gt;type == 'endoresment' &amp;&amp; $op == 'update') {

    // Does the user explicitly have create/edit endorsement content access?
    // By default, the OG module provides group owners add/edit/delete access
    // to all group content
    $ua_create = user_access('create endoresment content');
    $ua_edit = user_access('edit own endoresment content');    
    if (!$ua_create &amp;&amp; !$ua_edit) {
      // Show access denied message, and, interestingly enough, 
      // also sets the permission for the edit link.
      return NODE_ACCESS_DENY;
    }
  }
}


Question 2 is similar, but just need to change $op == 'update' to $op == 'view'.

I'm curious to see if anyone posts a better solution (other than fixing the OG module).