well, one thing to know regarding our plugin is that we intercept the_content filter, if I recall right, and replace it with the textbox and whatnot for our chat. If you’re needing to have it segmented like that on a tabbed setup, it may be best to have one tab be a WP_Query for the tab and the specific chat room that was set up for it.
CSS wise, that’s all going to be primarily controlled by your own theme. We can’t predict how it will be with every theme, especially one like this that separates bits out into tabs, so we leave the css pretty minimal.
Hope that helps, but ask more questions if you need info.