I don't see anything here that points to ANY problem with the transmission, and that includes the torque converter.

I do think you should change the transmission fluid. Changing only what's in the pan changes about 7 of the 18 quarts this transmission holds. I don't understand your hangup about the pan, why do you need to remove it? Did you read the link I posted that shows how to change ALL of the trans fluid without removing the pan?

As others have pointed out you may have a failing catalytic converter. That can hurt engine power and make various noises.

 

Im hung up on the pan due to my suspicion that the original owner was in there first and over torqued the bolts, what else could be lurking in there?

And thank you for the link, I now have a Sunday project.

Thanks everyone