The short answer to both questions is NO. The ADCs found in the PIC32MZ EF work great. Please use one of these devices instead.
The PIC32MZ EC ADC has a design flaw that limits its performance (maximum throughput rate: 125 KSPS, effective number of bits: 7). See the “PIC32MZ EC Family Silicon Errata and Data Sheet Clarification” document for more details. The ADCs found on the PIC32MZ EF devices are 12 bit and have a maximum sample rate of 18 MSPS. There are also many more configuration options for these ADCs.
The MPLAB Harmony Configurator (MHC) makes all PIC32 ADC configuration options available to you. If you try to use a configuration option not supported for your device, you will get this warning message:
"Warning: Driver implementation is not available. Only pin management functionality is enabled in this release."
Use a PIC32MZ EF device (instead of the PIC32MZ EC) to eliminate this warning.