berben4 - Thank you for the code correction. As far as the link code you require, you can link directly to the chat room from any page on your site (outside of vBulletin) using any of the link codes provided in your AddonChat account control panel (Home -> Chat Room Link Code) and under Settings -> Site Integration -> Who's Chatting you can find the Who's Chatting link code.
dodjer42 - The Chat Box you're using looks like a stateless chat room and functions much differently than AddonChat. While it would be possible to place the chat room on the main page, I wouldn't advise to do so in this manner as whenever the user moves to a a different page, he/she would lose the socket connection. There should be absolutely no performance problems with Firefox 2 -- in fact, we use Firefox 2.0.0.14 on all of our development systems for primary testing under Mac OS-X, Vista, and Win XP.
DiesellMinded - Already on the suggestion list for the 8.1 update. When the feature is available, we'll be sure to include it into the vBulletin integration script.
nwingate - Good suggestion, I'll add it to our list

Thank you!