DS multiple outputs

Just one more clarification on using the balanced and unbalanced out of the DS. My new configuration is balanced out to my amp (Ayre K1x pre and Ayre monoblock amps)

I also have the single ended going to a switch box so when I play the speakers the switch is turned to an open position so the single ended terminates in air. I presume this configuration is equal to no single ended input connected. My quibbling concern is the un-terminated rcas might interact still. First as an antenna, and second like other switch boxes mine (Schiiit) has a box ground common to all the single ended outputs and inputs. So from the DS’s perspective the left and right single ended grounds are shorted together. Should this have any effect on the balanced out?

Besides the interactions you mention you are getting the cable capacitance of both cables on one side of the transformer and only one on the other side. With most cables this difference isn’t significant, but with high capacitance cables it could be (say greater than 1nF bulk capacitance.) The tying more grounds together will cause more ground loops, but once again this may or may not be a big deal in your system. With my satellite receiver (which has three grounds: the AC mains, the phone and the satellite) in my system I definitely need balanced connections everywhere to nuke the expected hum and noise. Without it, single ended connections work fine everywhere.