Reinstalling iTunes is totally safe, if you're that worried just back up the iTunes library folder before reinstalling. The library is stored there, the app merely reads the library from that folder.
Under normal circumstances I would totally aggree with you - but, at least for me, things have changed with all the cloud services, in this case iTunes Match.
When I did a ML clean install last week I afterwards imported my iTunes library as I did many times before and you have also recommended. Everything looked fine and like before until iTunes Match started its matching process.
Once it was finished I had around 1200 duplicates in the cloud. The library (and the folder itself which was organized by iTunes) before was clean meaning I only had a few duplicates due to redundant songs in some albums. All the added duplicate songs also were slightly different versions than their original counterpart (a few seconds longer or shorter).
Reason was that iTunes somehow matched a lot of songs in a different way in comparison when they were originally added to my library, meaning a different song version was matched (now both versions were available in iCloud). This was a big mess and is caused by the fact that iTunes Match today matches some songs differently as for example one year ago (Apple might call it an improvment of the matching routines).
This issue doesn't come up when iTunes does its weekly matching, it only happens when you add songs to the library and though iCloud twice (by accident or simply when doing a reinstall) with a more or less large time gap in between.
Once you search the Apple support comunity, you see that this seems to be a common issue.
