Well, I think this chapter is closed. After taking the old Ex back to the transmission shop and going over my issues in detail - transmission fluid blowing all over the exhaust and smoking, the TCIL flashing even with the new transmission, TCC issues, the problem seemed to be a clog in the valve body on the used transmission I was sold. They took it apart and completely replaced the valve body and solenoids for free. So far, it's running incredibly well. All the gears, torque converter locking up fine, really smooth shifts. The shop owner apologized pretty profusely for his mechanic not taking it for a long enough test drive and based on the mileage, they definitely drove it all over the place this time. Overall I'd say I'm pretty happy with the shop, but mostly I'm happy to have the old thing back on the road. No doubt in my mind I'll get the engine to 300,000 now.