I'm not sure if I understand your message correctly. This is how it looks like to me what you're doing:
- You have a sidebar "Primary widget" only defined at the homepage
- You have a widget "News & Events" put into the sidebar "Primary widget".
- You only want to show the widget at the homepage.
It looks like you're done already. basically DW is not necessary here. It's a different approach of handling widgets by specifying sidebars, not widgets.
However, also what looked like you have done:
- Defined the sidebar "Primary widget" on all other locations
Now you're using the DW approach. Not touching the sidebar, but only the widgets. The config you have to do now in DW is for the "News & Events" widget:
- Set everything to 'No' (use the Quick setting at the top)
- Switch "Posts page" to Yes when your posts page is the homepage OR tick the checkbox belonging to the page under the static pages section when you're using a static page as your homepage.