With that in mind. I would definitely pick a different angle for the final image. straght on angles can be confusing if you’ve never seen the model in 3d.
I would can the veins on the end of the mask. It would be very difficult to make them look like veins. If you wanted to try though, you might want to fade some of the skin texture into the end piece a little and add some SSS. That would pull more of an organic feeling into the end. Putting veins over a piece of metal probably wont work well.
That is a strange problem with rendering you have. Rendering at higher resolutions does make low-res textures seem a little blurry. Could that be the problem?