The setup you have illistrated would IMO be the ideal setup except get rid of the MPI switches and use the JR charge switches. The failsafe switches are nice but will drain your battery slightly when in the off position and are more expensive. The odds that 2 switches are going to fail at the same time is nil. I run almost a identical system to this and am very happy with it. The RX goes atop of the Expander and the Expander has all the connections.

SHawn