Let's make things clear...

Once you load the Bootloader firmware in the PIC using ICSP with EPIC.. you'll no longer need the EPIC... just the Bootloader circuit in the MCS Help File. You'll program your PIC with that circuit Via your RS-232 (DB9) Pc connector.

Yes you'll need to use DEFINE BOOTLOADER_USED 1 line at the top of your code if you use Bootloader... not if you use ICSP with EPIC