Why can't I just right-click on a sidebar widget and select remove? You have to find the entry in the My Widgets list or under Maintain applications.
I had 3 sidebar widgets that didn't show in the My Widgets list, to get rid of them I had to install them again (re reboots) then I could un-install them. I still have 2 I can get rid of..
If they are installed via the policies, it should have something indicate that instead of just hiding the remove button. I have some with no remove that are no longer covered under a policy.
Also I get the workspace to jump to the tab with the widget catalog on it every so often.
I don't look forward to supporting salepersons with this.