Thanks for the exhaustive feedback! I really appreciate this.
For tank sag, I posted a photo above. Would it still be reasonable just to have the tracks touching the three middle road wheels?
For the chipping: I was thinking of applying a lighter green to simulate the scratches, and then a black-brown color to simulate the deeper damage (thanks for pointing this out btw! I was not sure what color the metal used for armor plate was. I assumed that they were a silvery color that quickly rusted into a brown tone). I'll try applying the chipping later with a sponge and a fine tipped brush
Ditching log: yeah, thanks for pointing that out. I had someone else point the obvious flaw I neglected to notice. The only fix I can think of now is to paint two rings around the log to simulate the straps (but the woodgrain is textured on the log so I might have to sand a bit of that off). Or maybe I can add some tape. I'll see.
As for the MG: Is it right to assume that there was an initial batch of Russian T-55As that did not receive the mounting? I can see from the instructions that Tamiya does include the T-55A cupolas with mounting but tells you not to use them for the Russian Marking options.
All of these feedback really makes me want to purchase a Miniart T-55 though. I keep hearing it has all the bells and whistles out of the box. Thanks again!