Turtle Island is also a regional cultural concept alongside the Medicine Wheel, though Turtle Island is from a myth and the MW is a religious practice, and while generally respected, does not have meaning for most of the Indigenous peoples of TI. It's not very representative of a continental movement unless multiple cultural elements from many peoples are being represented (consensually).
Perhaps when revolution comes and we give the Indigenous people and Blacks self-determination, maybe they would prefer to be represented as several separate nations/states.
Nobody will be "giving" us anything, you just won't be able to tell us what to do anymore.
Do the native peoples want to strive for Pan-Indianism? And if so, what does Pan-Indianism mean to the native peoples and what do they want (and/or not want) from being unified?
Unity is a tool, a means to an end. It is not an end in itself. This question is too abstract to provide meaningful discussion unless you are attempting solve a specific issue, like defending a resource from exploitation or extirpation.
Something like pan-Africanism can be spoken about more broadly because African states are mostly run by Africans themselves, unity would be a specific tool to prevent continued exploitation of the continent as a whole.
So I guess the question is why are we trying to build an identity around a unity practice that does not exist? Detached from practice it comes off incoherent, at best. AIMs symbolism is also subject to criticism from the masses AIM operated in, and its successors seek to operate in. Inform yourself with the masses, test, criticize, change, cycle.
I think that sub would do better focusing on the history of existing flags or editing flags of existing movements given their conditions.