Can I connect the MASTER1 output of the unit to the RCA input of the amplifier by using the XLR-RCA conversion cable (conversion plug)? Or, can I connect MASTER2 output of the unit to the XLR input of the amplifier by using the RCA-XLR conversion cable (c

Performance of the connection via conversion cable cannot be guaranteed.
Connect the MASTER1 output terminal with the amplifier having XLR input. Connect the MASTER2 output terminal with the amplifier having RCA input.
Connect the BOOTH output terminal to the amplifier having TRS input.