First, It is good that you removed the scripts, but should also remove the line you added. The way plugins work (well written plugins, anyway) is they first check to see if jQuery has already been loaded. If not, they will load it for you (the correct version, in the correct location). if it already has been loaded, it says 'hey thanks' and moves on.
Second, the issue with things flopping around all over the place. This is because your triggers have the following css:
Try removing the float, clear and width from the triggers and placing it in a wrappign container like so:
<div class="floatwrap">[expand title="title"]target content[/expand]</div>
and then simply add the floatwrap class to your css:
Give that a try and let us know how it goes!