[Lionel]

This has nothing to do with SEO

for broken links, if you do not want to display errors, put in the error documents in your htaccess. It's more elegant anyway

ErrorDocument 401 http://site.com/page.htm
ErrorDocument 403 http://site.com/page.htm
ErrorDocument 404 http://site.com/page.htm
ErrorDocument 500 http://site.com/page.htm
ErrorDocument 503 http://site.com/page.htm

and create the static pages, putting whatever you want in there. Me i put images of the categories. You can also put a sitemap.php instead of page.htm if you have that mod installed. Do a search on the net to see what those errors are and to create pages with proper wordings.

Now for that error 33 it's a little more involved although simple. Go into include/func.php and just change that line in func.php to what you want, replacing the error_message.php?access_denied&id=33 with

home.php

# Error handling
#   
	if (!$product || !$categoryid) {
		if ($redirect_if_error)
			func_header_location("error_message.php?access_denied&id=33");
		else
			return false;
	}