Rolf,
In the zip file that you download, there should be multiple additional zip files. One is the main component, the others are profile plugins and another is the modules. The main component file can be installed directly, but the profile and module zips need to be unzipped and installed individually. Because of the {JFBCxxx} tags, we don't install them all by default as many sites don't need them.
When you use the {JFBCxxx} tags, they will include a div around them automatically on the page. JCE shouldn't be modifying them though in the text area. If so, that's not normal.
As for controlling the position and dimensions, the only way to do that is using the modules or the tags. There's no defaults you can set for all of them as there's so many different ways you might want it shown that you should set it explicitly. If you leave the tag without dimensions, we use Facebook's default dimensions, which are different for each widget.
Hope that helps,
Alex
Where are the plugins?
