The Intel Management Engine (ME) is a separate microprocessor that is used to manage the system. While it is true that, on vPro-enabled systems, the ME hosts the vPro functionality, it also hosts other functionality that is crucial to the proper operation of the system.
Intel Rapid Start is unnecessary in SSD-based systems (IMHO). Intel Ready Mode Technology essentially replaces Intel Smart Connect Technology. Intel Smart Response Technology is part of (hosted by) Intel Rapid Storage Technology.