As the switch is never plugged into itself, it doesn't matter whether the MAC addresses are the same or not and as far as other devices are concerned, they know to reach whatever destination, their MAC address table says to go to MAC addess xx.xx.xx and there will never be 2 MAC addresses on the same segment.
If you do a "Show Chassis Mac-Address" it will show your base MAC address. All MAC addresses come from this and from here the system allocates MAC addresses to interfaces. There is a limit as to how many the system can allocate and some will be used internally by the switch, but you may find your MAC addresses are increasing by 1.
In short, there should be no need to change these MAC addresses for your system to function normally, just configure the L3 addresses and your switch will just work.