OK, well people are probably trying to hack the site through the form and are entering the correct captcha and security question answer.
The validation wouldn't prevent those fields from being entered. As it is applied now, it should prevent invalid email addresses, so that field having bad values is surprising. The comments and name fields don't have any specific validation on them.
So, are you asking how to prevent specific characters from being inserted into a field?
You can do that by changing the validation type.
So for instance if you changed:
$WAFV_Errors .= WAValidateRQ((isset($_POST["Contact_me_group_Name"])?$_POST["Contact_me_group_Name"]:"") . "",true,1);
to:
$WAFV_Errors .= WAValidateRT((isset($_POST["Contact_me_group_Name"])?$_POST["Contact_me_group_Name"]:"") . "","<, >",true,1);
Then added:
$WAFV_Errors .= WAValidateRT((isset($_POST[Contact_me_group_Comments"])?$_POST["Contact_me_group_Comments"]:"") . "","<, >",true,6);
Then you would have validation to prevent entering < or > into either the name or comments field.