Question I wish to have have 8 ADAT inputs + my Unity FX returns. How do I configure the UnitY card

You will discover some (minor) problems / difficulties with this:
  1. In order to get all eight track into slot3 of the 02R you mustselect card in slot3 instead of the internal analog inputs (DIGITAL I/0 page 2). This means that you must disable Extended Routing (ExtRt) and thus you cannot return the UnitY engines directly to the Stereo LR bus nor to 21/22. 
  2. The 02R slots have "only" 8 inputs each, but for both slot3 and slot1 you have 8 dry tracks from your digital multitrack plus 2 stereo outs from the UnitY engines = 12 signals! - for 8 inputs...
We have two suggestions:
  1. You can route (mix) the external inputs channel 5.6 and 7.8 to ch 5.6 on the UnitY card and route both engine outputs to ch 7.8 (Not really useful unless both track 5.6 and 7.8 are stereotracks and/or don't need separate EQ, Efx etc.). -- or --
  2. You can route both UnitY engine outputs to "out5.6" or "out7.8". Thus it will appear on the digital output of the UnitY card. (You can then set the UnitY card Digital output to ADAT instead of TDIF and receive the reverb etc. via an ADAT interface - to AES or analog inputs).
This hopefully gives you an idea of the possibilities. It is not ideal but there is no better solution with the 02R. Below, some helpful drawings:

Slot 1, Standard Routing:

Slot 3, Standard Routing:


Slot 3, Extended Routing:


Slot 3, Extended Routing with Finalizer: