You can change the shortcut. Theres also the bookmarks bar. As for a sidebar its not coming back. It is a lot of work implement in the new renderer and very few people made use of it. I sure didn't. In fact test had shown that the lions share of people don't even use bookmarks and my personal experience as a computer tech can back that up. The only reason bookmarks returned at all was because of the number of people that complained about it. Still, only a fraction of users use bookmarks and only a fraction of them use the sidebar. Its just not worth the effort to build it. Someone might make an extension for it though. You never know.