If the blade cuts through the mat, can tape, etc., be attached to the back so the mat can be reused?

Can rough material be cut?

Can different types of material be attached to the same mat for cutting?

Can multiple sheets of material be overlapped and attached to the mat?　

Can the Cutting mat or Scanning mat for the ScanNCut (CM series) be used in the ScanNCut DX (SDX series)?

I find some scratches outside the grid area (the attaching area) on the mat. Why is such a scratch attached on the mat?