Your setup for only one pair of speakers is correct - connected to the FRONT output(s) and NONE in the speaker menu.
Both PL outputs for FRONT carry the LEFT AND the RIGHT signal - on all active speakers (exept the 2500s) you decide "L" or "R" on your speaker.
The MCL2p is a stereo component, there is no need to use a Y-connector when you connect it to one of your front outputs!
You will need a FULLY MOUNTED PL-Cable (the original PLs from the early 90's / the MK2 3,5mm type / the new 5.5mm double shielded type have all 8 pins connected)