One thing to consider on the tranny cooler is winter driving. The tranny will delay shifting into 4th and lockup when cold to warm up the engine quicker. It uses its own heat and heat from the radiator to warm up the fluid so it can shift sooner. In the summer climbing hills it might be a good thing. If you hook one up, I would keep the oil flow through the radiator.
Our 95 RHD Legacy wagon AWD 4EAT (476k miles mail car) the original radiator lost the fins between the tubes on the lower third of the radiator. On the aftermarket replacement after a few years the upper hose plastic tube started to crack around the tube where the clamp was. The next one has been in a lot of years and is fine.
The OE radiator fans have one 4 and one 5 blade units. I replaced the 4 blade with a 5 blade and motor. I think the 4 blade is the Main Fan and the 5 blade is the Sub Fan. The 5 blade is listed under A/C parts on RockAuto. I just looked and they show 5 blades on both fan assembly's. ? I order three of those (for spares) and then swap one of the motor and fan to the old 4 blade shroud. They move a lot of air.
In case you don't know about this there are two green test connectors under the steering wheel. You have to remove the panel. Connect them, turn the key to ON (no start) and the ECU will run the fuel pump, solenoids, ac compressor clutch and then both fans on low speed, then high speed then off and repeat the cycle until you turn the key OFF. Good way to see if both speeds are working on both fans.