Configuration / settings location and backups

Q1) Which files in C:\Users\<your account>\AppData\Roaming\Microsoft\Internet Explorer\Quick Launch are used by TLB?

The folders are the TLB menus. Shortcuts to run something. tlbdata.xml (hidden) files contain menu/toolbar items/menu settings and layout. setup.ini caontain the TLB settings. namespace.fld files are the shortcut for the virtual folders.

Q2) if I backup the files needed by TLB from those locations, do I also still need to use TLB's built-in backup utility?

The built-in backup utility do the exactly the same thing - saves all files and folders from the toolbar folder into the single file. The only note, you must to close TLB before restoring TLB from your own backup.

I have Windows 7.

The folder "User Pinned" in the Windows 7 contain the pinned items on the taskbar.