Wish I could answer all of your questions but only know something about the 'Okie" assembly. That assembly is an after market item used to replace the seal and bushing at the front end of the torque tube. In my experience the only way I found out that my seal was leaking was the trans fluid would run down the tube and into the differential. It would leave the trans dry. If you are apart already I see no harm in putting in the 'Okie' assembly as it is a lot easier than doing it when the drive line is in place.
If it were me, I would put it all back and drive it then you can diagnose if anything is wrong back there. However I would still put that 'Okie' in first, can't go wrong.
Bill
