Since you wrote a very long post that made some very important points, I would like to highlight what I consider to be the most detrimental flaw if the current design:
A fairly large number of users do use Bitwarden’s browser extension as a bookmark manager. In fact, for someone who routinely autofills using the keyboard shortcut (or other methods that don’t require opening the extension), the main reason to open the browser extension popup is to search for a site and launch it.
For this common use-case, the work flow is now significantly degraded.
One must now scroll past all of the “Autofill Suggestions” and Favorites (or type a much longer search expression to narrow the results) to access the launch icon for a site that one wishes to open, which makes the user experience much more inefficient and unpleasant.
My suggestion would be to either restore a separate tab for search results, or to simply disable/hide the “Autofill Suggestions” and “Favorites” areas when displaying search results on the new, unified “Vault” page.