How are software protection techniques affecting the performance of executed software?
this depends how hard-to-crack a specific technique is and how it is implemented in the executed software. For example: It is a bad idea protect code by encryption and to decrypt the code everytime if the code is called in a loop. Instead this code should be decrypted once before the loop is started. In general, good protection tools permit the fine tuning of the protection level in dependence of performance issues and real demand.