"I can't seem to upscale model without screwing portrait" in the first file you provided, unit animation and portrait animation are included in the same file in order to save space, wc3 model usually have different file for portrait & unit because portrait model usually have more details, e.g batTroll got ear ring in the portrait but not on the actual unit. In the model file, there is a "camera object" which is used to preview the portrait in game, when you upscale your model, you have to move this camera object so it shows a correct preview.
Having a separate portrait should resolve this problem.
As for your second request, I don't understand it. You different portrait following the flying/on ground state?
Also when you upload a model with custom texture, you need to upload the texture.