Can I cancel iTunes Match and subscribe again without reuploading my music? If I decide to cancel iTunes Match for a bit and then resubscribe do I go through the whole 'match' process for my music again?
I actually wrote an article on this.  The relevant part:


  When you end your iTunes Match sub, you can only access songs you’ve
  downloaded, they will not be available to download after the sub ends.
  You can continue to play the songs that exist on your device.
  
  Your iTunes Match library will only be stored online for 30 days after
  you cancel.


http://demianturner.com/2015/11/itunes-match-vs-apple-music/