Alright, I was thinking about a solution to your above problem aswell; atleast half of it.
First you need to create a custom navbar link.
To do this, log into your admin panel
Go to style Manager, and select edit in the dropdown menu next to the style you would like to edit, and hit go.
Then expand the navigation/breadcrumb template.
Edit the Navbar template.
Find the Navbar links, most templates mark the beggining of navbar links with some form of comment.
Place this in the order you want it to showup on the navbar (i.e. if you want it to show up before the QuickLinks link, place it above the code for quicklinks)
Code:
<td class="vbmenu_control"><a href="http://ENTER URL HERE">ChatBox</a></td>
The url of your chatbox should be
http://yourdomain/misc.php?do=cchatbox
(assuming this is the location of the forum, ie it isnt in a subdomain)
If you want to make the chatbox "not appear" anywhere on your forums, then place something that isnt recognized in this option (locted: admincp > vbulleti options> cyb - chatbox)
Code:
Show ChatBox on (comma separated THIS_SCRIPT locations)
Blank to show on all pages (not recommended because of server load)
I placed quite a few things there in an attempt to make it display on a specific forum. When it didn't recognize it, it simply did not display the chatbox. I'm not sure if this is the most orthodox way, but it works.
I'm not sure if all of this is 100% accurate. Its the best help I can offer.
Good luck