This is good because it uses a lot of reference material. Lots of observation. But i'm sorry to say it's lacking insight and at least one or more things are wrong. Or the thought wasn't written out correctly i guess.
The pure observation part about the two sets of eyes thing. The top set is just part of the cloak that further shields or, bulks up, susanno. Its just a shield hood type thing its not an actual face. The real face is in that mouth and the body is under that cloak/armor. It's just a hat not its face.
The thing with the gem on the forehead is also observant but it doesn't really make sense.
And I would say that seeing the the changes in susannos appearance coinciding with increases in power are obvious. But better to point them out in the fashion you've done.
But we're still lacking insight. Sort of poking at a theory that the changes occur because of hashiramas cells doesn't hold water.
Sasuke's changes with susannos appearnace, have coincided with his leaps foward in power and hatred.
The skeleten forms against the kages at the kage summit meeting. And then the cloaked form when he faced danzo. His breaking through danzos seal. With force of will and greater hatred. AND. he gets a more powerful chakra and susanno. Karin mentions every single time sasukes chakra gets more evil. (sry i don't have page references but if u go to these fights they are there.)
The rinnegan being another leap foward from the sharingan was mentioned. (someone already mentioned this in the thread).
And connecting these 2 things is insightful. the rest is sorta blagaeraekrlaj;dklfajdklfajdl;jfbffffffffffff.
Very observant. Lacking insight. Going to say i agree and disagree.