1. Getting your saved session back.
Type "about:config" in the title bar, hit enter, and click the "I'll be careful" button.
You'll see a screen full of lines for various setting names like "accessibility.typeaheadfind.enabletimeo
In the search bar at the top, type "browser.sessionstore.enabled" and hit enter. If you see an empty screen below the search bar, then you have the same problem I (and many other people) encountered: your browser.sessionstore.enabled setting vanished with the upgrade. So, you need to put it back...
Right-click somewhere in that empty space below.
From that right-click menu, select New -> Boolean.
In the popup window, enter browser.sessionstore.enabled and click OK.
You can close the "about:config" tab now. All your other tabs should immediately reappear.
2. Getting your title bar back.
Right-click on the top-right or top-left, on the same bar where all your tabs are, but not on one of the tabs. Anywhere to the right or left of the tabs, in the gray area or the buttons that are there.
From the right-click menu, choose "Customize..."
On the customize screen, on the bottom left, click the "Title Bar" button.