i heard a "POP"

RPMmachine said
the outer input shaft of the transmission wiggles a tiny bit though, i dont know if this is normal or not because im no trans expert.

I bet it is inside the torque converter. I had one go bad on my Ford truck years ago I used to own. No metal shaveings, fluid looked ok, etc....

The problem I had was the torque converter would "shudder" this might be the same as you describe "rough".