Replace sidebar with another one

[Attitude5ire]

1) You can permanantely show the sidebar by disabling the collapse feature.
2) Sidebar is totally optional, i think it uses YUI framework cant be sure the JS you saw might not only be for sidebar could be a framework which connects to many other things.
3) Possibilities are certainly, you can custom mod sidebar and add some stunning HTML static elements, depends on vision. But you can obviously lead by example and set standards urself than look for inspiration.