Thank you for your direction! it is exactly what I needed.
This is what I did:
1. In function decodeURI(), I did something slightly different than your suggestion, but same idea
//jmw-commenting out setting username and e-mail
if ($my->username) {
$this->_userid = $my->id;
$this->_usertype = $my->usertype;
//$this->_tname = $my->username;
//$this->setUser();
} else {
$this->_userid = 0;
$this->_usertype = 'Unregistered';
//$this->_tname = $this->decodeData_Charset('tname');
//$this->_temail = $this->decodeData_Charset('temail');
}
// jmw-adding next 2 lines to allow setting name and e-mail in ALL situations.
$this->_tname = $this->decodeData_Charset('tname');
$this->_temail = $this->decodeData_Charset('temail');
2. In function setUser(), I made one line change:
// jmw-rewrite following line to show name, not login username
//$this->_item['name'] = $this->_use_name ? $user['name'] : $user['username'];
$this->item['name'] = $user['name'];
By the way, I tried just setting the use name parameter but then it used the name set for the login instead of the name for the comment. So, I made this change, and it displayed the name the commenter input.
3. In function set_tmail(), I made the following change:
//jmw-setting to $value no matter what
//global $my;
//$this->_temail = ($my->id ? _JOOMLACOMMENT_AUTOMATICEMAIL : $value); /* change also modify - ajax_quote ! */
$this->_temail = $value;
I also turned off the {editbuttons} in the template so that people couldn't edit other people's comments since they use the same login.
Please let me know if I did anything "dangerous".
Thanks again for your prompt and helpful advice!
-Min