Question Should I use an impedance converter to connect when connecting a AES/EBU signal to the S/PDIF in of my TC device When sending an AES/EBU 110 ohm signal in/out of the D-Two, is it necessary and/or desirable to use impedance transformers to convert the 110 ohm signals to 75 ohm

Both yes and no. If your AES signal needs to be transmitted through long cables you might want to include an impedance converter in the loop. In case of short cables there should be no problems in using regular 110 Ohms cables directly to the in/outs.