I did not have to save the Tunes and playlists. Once I'd installed the latest version of itunes, it found them all.
As you suggest, the back up was "just in case". As it takes forever to load stuff, I thought a specifically created back up would be worthwhile, so I didn't have to go looking in my normal back up files.
However, after re-installation, it found 2 of everything, so I had to do the "Shift, File, Display exact duplicates" routine described in Itunes help, and then delete the unnecessary duplicates - which I identified by the date of their creation. - Date added in itunes terms. (If you do not already have date added along the top control bar, or whatever they call it, then right click on the bar and add it from the available list).
Hope that helps.
AO