what is the function of the Craftclone and BDPstamp application in the toolbox?

To clone aircraft (clones _SQD models and info to make all the other instances) and stamp the all the BDP files with the correct date. These are used during install.
This is not normally used at other times, but if you have changed something or corruption occurs on the hard drive it may be necessary - don't click it if you have no good reason to.
Very occasionally we may tell you to try it in support, but rarely.