Yes the problem is usually the conductor plate. The issue here is that it can not be replaced with a used unit. But you can easily repair the one that you have by sending it to someone who fixes them.
You have a couple of options.
You can use some on eBay that offers 722.9 transmission repair service. The pros of this service is that if there is an issue you will be protected via eBay buyer policy. If you are looking for the cheapest price this is the best way to go. Note, that the listings show as REFURBISHED, but what that means is that they will refurbish your old unit.
I thought of sending it to Circuit Board Medic but they have a message on their website saying they only take care of two error codes, Y3/8N1 and Y3/8N2. I also tried calling them but could not get anyone on the phone. I called a company in Cali and I was told it the only way to know if the TCU in my car is repairable or not is to get the 10 digit valve body number or the EHA number and check it? I'm very confused now. I thought the year, make, mode and the error codes would be enough.
It is very likely that the lights are on becasue you cleared the codes or because the battery was disconnected. What you need to do is start the car and turn the steering wheel all the way to the left and all the way to the right twice.
That should reset your abs, ets warning lights. If they don't get reset, read the codes from those modules.
The oil leak is a concern. If it is transmission fluid, your car will go into limp mode again. Investigate the leaks and maybe post a couple of pictures.