Hundreds of Notices and Warnings in PHP code
<p>I've inherited some legacy code, within which if I turn on:</p>

<pre><code>error_reporting(E_ALL); 
</code></pre>

<p>I get literally hundreds of messages all over our site, all of them like:</p>

<pre><code>Warning: include_once() [function.include]: Failed opening '../inc/variables.php' for inclusion (include_path='.:/usr/local/lib/php') in /var/www/html/xyz/xyz/xyz/payment.class.php on line 9

Notice: Undefined index: validateArrayName in /var/www/html/xyz/xyz/xyz/payment.class.php on line 3417

Notice: Undefined variable: objInstructor in /var/www/html/xyz/xyz/xyz/classes/metatags_class.php on line 44
</code></pre>

<p>Is this a bad thing? The site works fine otherwise, but I'm wondering if its </p>

<pre><code>(a) a really bad thing and 
(b) even if not, is it worthwhile to go fix all these issues?
</code></pre>
