Help With Audit log Setup
Both of these are forms, so you can do something with a hook_form_alter.  The easiest thing to do is do a View Source, find the form, and look at the ID on the &lt;form&gt; element.

The permissions form is user_admin_permissions.  My suggestion would be to alter the form to add a new submit handler, eg

function mymodule_form_user_admin_permissions_alter(&amp;$form, &amp;$form_state, $form_id) {
  $form["#submit][] = 'mymodule_log_permission_change';
}


The settings changes are going to be tricky, as they are spread across many, many forms.  The idea is the same, you just need to figure out whether you are on a setting for or not.  You could alter all of the important setting forms, or you could try using the base hook_form_alter() and check the $form_id.  You could also try checking the URL from withing the submit handler, as many of the settings live under /admin.