Converting Vertex and Index buffers to a File Format
No idea about DirectX, but in OpenGL the buffers are just a block of binary data so you can easily load and save them.

In any 3D framework, changing the object position to achieve a different relative arrangement of a scene is not done through the view matrix (that represents the camera position and viewing direction) but through the model matrix of each model. Note that the vertex and index buffers stay unaffected by matrix transformations, that is the main benefit of such pipelines.

Perhaps you could do your study with less effort using a 3D game engine, to list just a few:


https://godotengine.org/
https://www.unrealengine.com/
https://unity.com/


I am not aware that any of them would support loading the raw buffers straight away, but they can load OBJ files. OBJ is one of the oldest text-based 3D model formats. It has a simple structure, so you can easily convert your buffer data to an OBJ file.