Security Assist - details on setup

Re Security Assist:

1 - May I confirm? There can be many conditions, but there can be just one rule per page?


2 - Regarding the conditions:

Is there any reason to both "allow" and "deny" the various parties allowed and not allowed?
Or instead, "Allow" is all that is needed, at least for simple access control?


3 - Detail regarding login / logout:

A - Can I safely remove two code blocks that are not in fact used? Is there related code that then should also go?

[ For example, this code block:
<?php if(WA_Auth_RulePasses("Emailed password")){ // Begin Show Region ?>
<p>Password information emailed, please check your inbox</p>
<?php } // End Show Region ?> ]
[ And:
<?php if(WA_Auth_RulePasses("Successful update")){ // Begin Show Region ?>
<p>Registration completed successfully, please log in to access the site</p>
<?php } // End Show Region ?> ]


B - Can logout code be not necessarily on its own page (as generated initially), but rather be incorporated into something else? If so, any necessary precautions / what minimal code?

As always, thanks, David