Using evince version 3.10.3 on Ubuntu 14.04. Tried every way I could think to change the default settings to remove the sidebar and set default view to fit-width.
1. Used dconf Editor to ensure show-sidebar and show-toolbar was deselected and sizing-mode was set to fit-width (see attached screenshot).
2. Created a new PDF file. I opened the file and saw that the sidebar was still there and sizing was fit-page.
3. I corrected the view and used Save Current Settings As Default to save the settings
4. Used File -> Close to close the file
5. Opened the file in Evince again and the sidebar was still there and sizing was still fit-page. I would have attached a second screenshot but the website doesn't allow more than one.
I have scanned the internet for this bug, but most responses were for much older versions and/or claimed to be resolved, though I couldn't find an explanation of how they were resolved. The closest thing I could find was a complaint about viewing size being saved at 80% instead of 100%.
Status changed to 'Confirmed' because the bug affects multiple users.