It looks like you've made up your mind on most of the features of your Sherman project. On feature choice number five, I'd suggest the T-48 rubber chevron track. It was the most used track in Europe. The T-54E1 that you talked about is the most common steel track. The easiest to mold would be either the T-41 or T-51, as the rubber pads are plain.
Nothing is final until we start the project. Right now is data collection, that's why we posted what we think we will do... subject to comments and feedback.
Because of the one piece track design, there are limitations on how the track pattern will show up on a two-part mould. Consider the scale of the model, there is no signification differences on the T48 and T54E1 with our current design method. Being that said, we are now switching to side-sliding moulds (3 part mould) to create track patterns on the front end of the track - about 4 to 8 tracks with patterns in the front will be visible. The rest of the tracks (upper and lower, plus back side) will remain the same as current one piece track - Our thinking is basically only the front is visible, other views/areas will be blocked by the upper hull anyway.
On choice number seven, you only leave two choices, unfortunately. Really, only one, as I believe the T80E5 was made postwar. Have you considered etched brass for the face of the T-66 tracks? Maybe not the entire track, but just the cast pattern detail that meets the ground? I seem to remember a company that made etched brass track for the Roco Minitanks years ago. Maybe something like that?
Even with the three-part mould method, the T80 pattern will not be very noticeable in our scale. We are thinking of a resin upgrade kit (with T66 tracks) later when the HVSS option is available.